8th grade algebra (square roots/fractions) help

[NHdisneylover]

DD13 is still learning German and has "that" teacher for math. You know, the teacher even the other teachers all complain about. This teacher is very hard for all the kids. She rarely writes on the board and she speaks VERY fast. In the end this boils down to DD not understanding a word of what happens in class and then she come home and googles to find out how to do the homework. Mostly this works pretty well (luckily DD is great at math).
This teacher gave the kids 26 pages of homework for Christmas break (yes, we are still on break--BUT we make up for it when the kids' summer vacation does not start until July 31). DD figured out most of it (with some help here and there form us) but there are a few things relating to square roots of fractions we just can't find how to do by googling (I am sure we are just not putting in the right terms). They fall into two seperate sections. I am giving three problems in each section to try to illustrate what the general idea is (not that I really know, obviously). I will do my best to explain the problems (I don't know how to make a square root sign on the keyboard) and am really hoping someone out there knows how to do this and can explain or point us to a website. They are simplyifying but are not supposed to solve the squares into decimals, etc. We do not need the answers but just need to know how to go about solving these types of problems. MANY THANKS

Section 1:
Problem 1: Sqaure root of 1/2 minus square root of 9/2

Problem 2: Square root of 4/3 plus 2 square root 1/3

Problem 3: 2 square root 0.05 plus square root 5/9

Section 2:

Problem 1: Sqaure root of 3 over square root of 5 minus square root of 3/25

Problem 2: 1 over sqaure root 2

Problem 3: 2 square root 3 over square root 5

 

[PlaneJoy1]

If you haven't already, watch this video for some basic explanations:
http://www.ehow.com/video_4987374_adding-subtracting-radical-expressions-fractions.html

For this: Problem 1: Square root of 1/2 minus square root of 9/2


I believe it can be rewritten as radical 1 over radical 2 subtract radical 9 over radical 2. This would make the denominators the same and you can subtract. So the answer would be 1-3 over 2 or -2/2 or -1.

I'm sure someone knows this more than I do and can let me know if I am wrong.

 

[mnrose]

DD13 is still learning German and has "that" teacher for math. You know, the teacher even the other teachers all complain about. This teacher is very hard for all the kids. She rarely writes on the board and she speaks VERY fast. In the end this boils down to DD not understanding a word of what happens in class and then she come home and googles to find out how to do the homework. Mostly this works pretty well (luckily DD is great at math).
This teacher gave the kids 26 pages of homework for Christmas break (yes, we are still on break--BUT we make up for it when the kids' summer vacation does not start until July 31). DD figured out most of it (with some help here and there form us) but there are a few things relating to square roots of fractions we just can't find how to do by googling (I am sure we are just not putting in the right terms). They fall into two seperate sections. I am giving three problems in each section to try to illustrate what the general idea is (not that I really know, obviously). I will do my best to explain the problems (I don't know how to make a square root sign on the keyboard) and am really hoping someone out there knows how to do this and can explain or point us to a website. They are simplyifying but are not supposed to solve the squares into decimals, etc. We do not need the answers but just need to know how to go about solving these types of problems. MANY THANKS

Section 1:
Problem 1: Sqaure root of 1/2 minus square root of 9/2

Problem 2: Square root of 4/3 plus 2 square root 1/3

Problem 3: 2 square root 0.05 plus square root 5/9

Section 2:

Problem 1: Sqaure root of 3 over square root of 5 minus square root of 3/25

Problem 2: 1 over sqaure root 2

Problem 3: 2 square root 3 over square root 5

I'm not sure...I'm a little rusty on this. However, I flat out guarantee you that if you google addition or subtraction of fractional square roots, you'll get quite a few hits. I'm constantly amazed at how much teaching information is out there on the web. Good luck!

 

[mnrose]

If you haven't already, watch this video for some basic explanations:
http://www.ehow.com/video_4987374_adding-subtracting-radical-expressions-fractions.html

For this: Problem 1: Square root of 1/2 minus square root of 9/2


I believe it can be rewritten as radical 1 over radical 2 subtract radical 9 over radical 2. This would make the denominators the same and you can subtract. So the answer would be 1-3 over 2 or -2/2 or -1.

I'm sure someone knows this more than I do and can let me know if I am wrong.

I think the answer is -2 over the square root of 2.

 

[Magic Mom]

DD13 is still learning German and has "that" teacher for math. You know, the teacher even the other teachers all complain about. This teacher is very hard for all the kids. She rarely writes on the board and she speaks VERY fast. In the end this boils down to DD not understanding a word of what happens in class and then she come home and googles to find out how to do the homework. Mostly this works pretty well (luckily DD is great at math).
This teacher gave the kids 26 pages of homework for Christmas break (yes, we are still on break--BUT we make up for it when the kids' summer vacation does not start until July 31). DD figured out most of it (with some help here and there form us) but there are a few things relating to square roots of fractions we just can't find how to do by googling (I am sure we are just not putting in the right terms). They fall into two seperate sections. I am giving three problems in each section to try to illustrate what the general idea is (not that I really know, obviously). I will do my best to explain the problems (I don't know how to make a square root sign on the keyboard) and am really hoping someone out there knows how to do this and can explain or point us to a website. They are simplyifying but are not supposed to solve the squares into decimals, etc. We do not need the answers but just need to know how to go about solving these types of problems. MANY THANKS

Section 1:
Problem 1: Sqaure root of 1/2 minus square root of 9/2

Problem 2: Square root of 4/3 plus 2 square root 1/3

Problem 3: 2 square root 0.05 plus square root 5/9

Section 2:

Problem 1: Sqaure root of 3 over square root of 5 minus square root of 3/25

Problem 2: 1 over sqaure root 2

Problem 3: 2 square root 3 over square root 5

I think it's like adding normal fractions.
Problem 1
You simpify each fration to the sqrt(1)/sqrt(2)-sqrt(9)/sqrt(2)
Simplify further. sqrt(1)=1 and the sqrt(9)=3
So now you have 1/sqrt(2)-3/sqrt(2)
The denominator is the same so you don't do anything to it when you subtract.
Subtract.
-2/sqrt(2)

 

[Jennasis]

My head just exploded.

 

[agnes!]

Check out youtube, they often have instructional videos, I bet they'll have one for this very subject. I've found youtube to be a life-saver when my DD wasn't getting a concept and had 'that' teacher.

agnes!

 

[PlaneJoy1]

I think the answer is -2 over the square root of 2.

Exactly - but any number over itself reduces to 1 or in this case -1.

 

[gregokdisney]

Try wolframalpha.com - it's amazing for computational questions.

 

[redsunfish]

I think it's like adding normal fractions.
Problem 1
You simpify each fration to the sqrt(1)/sqrt(2)-sqrt(9)/sqrt(2)
Simplify further. sqrt(1)=1 and the sqrt(9)=3
So now you have 1/sqrt(2)-3/sqrt(2)
The denominator is the same so you don't do anything to it when you subtract.
Subtract.
-2/sqrt(2)

That is exactly how I would do it. It can be simplified even further though as well:

Take that number and multiply it by sqrt(2)/sqrt(2) (which is the same as multipling by 1)

=-2*sqrt(2) / sqrt(2)sqrt(2)

=-2*sqrt(2)/2

=-sqrt(2)

Man, it's hard to type math equations on a message board!

Signed,
An Electrical Engineer who loves algebra

 

[Magic Mom]

That is exactly how I would do it. It can be simplified even further though as well:

Take that number and multiply it by sqrt(2)/sqrt(2) (which is the same as multipling by 1)

=-2*sqrt(2) / sqrt(2)sqrt(2)

=-2*sqrt(2)/2

=-sqrt(2)

Man, it's hard to type math equations on a message board!

Signed,
An Electrical Engineer who loves algebra

good catch, I should have seen that.

 

[worm761]

Here are some websites. they may not help your DD now but might in the future. If she ever needs any other websites/help feel free to PM me. I am assuming your DD is in 8th grade. I homeschool my DS who is also an eighth grader.

http://www.myalgebra.com/algebra_solver.aspx

http://www.freeworldu.org/Flashcards/CategoryListing.aspx

http://www.algebrafunsheets.com/home.php

 

[AmandaSparks730]

Her book may have a website to go to that has examples and whatnot. There are plently of math-help websites out there! Trust me, when I was her age, I *lived* off of those.

Not that I'm much older...

Maybe that's why I'm not doing so well in Trig!

 

[NHdisneylover]

Thank you so much everyone. There are some great websites here that I am bookmarking for future--and I appreciate the help in what terms (in English) to look up I think we've got it now.

Her book may have a website to go to that has examples and whatnot. There are plently of math-help websites out there! Trust me, when I was her age, I *lived* off of those.

Not that I'm much older...

Maybe that's why I'm not doing so well in Trig!

Thanks Amanda. Normally that would be great advice.I wasn't very clear earlier. We moved to Germany about 10 months ago and the kids started attending a German school this fall. None of us spoke any German when we got ehre (we only knew we were comming about 8 weeks in advance). The problem is that the text book is also in German (and I have not seen any websites listed, but if they did I am sure they would be in German as well). DD's challenge is that she is attending a German public school while learning German as she goes. My kids are braver souls than I am

 

[dawson5]

This might not be what you are looking for but I found a program called bagatrix. It is a "pay for" program but it's good from what we have used of it. We type in the problem and hit the solve button and it shows you step by step on how to solve the problem. They have algebra I & II, geometry and I think a few more. (I would do the program in it but it's on the computer with the dead hard drive.)

Also I have to wait for the boys to get home but when they do I can ask. We have a phone number to call for homework help (I know this does not help you in Germany) but I think they might have a website that can help. It's through the Rose Hulman Institute.

 

[agnes!]

Thank you so much everyone. There are some great websites here that I am bookmarking for future--and I appreciate the help in what terms (in English) to look up I think we've got it now.

Thanks Amanda. Normally that would be great advice.I wasn't very clear earlier. We moved to Germany about 10 months ago and the kids started attending a German school this fall. None of us spoke any German when we got ehre (we only knew we were comming about 8 weeks in advance). The problem is that the text book is also in German (and I have not seen any websites listed, but if they did I am sure they would be in German as well). DD's challenge is that she is attending a German public school while learning German as she goes. My kids are braver souls than I am

Can you maybe order an 8th Grade Algebra book/workbook in English?

agnes!

 

[NHdisneylover]

This might not be what you are looking for but I found a program called bagatrix. It is a "pay for" program but it's good from what we have used of it. We type in the problem and hit the solve button and it shows you step by step on how to solve the problem. They have algebra I & II, geometry and I think a few more. (I would do the program in it but it's on the computer with the dead hard drive.)

Also I have to wait for the boys to get home but when they do I can ask. We have a phone number to call for homework help (I know this does not help you in Germany) but I think they might have a website that can help. It's through the Rose Hulman Institute.

Thanks. I think that software looks like it may well be worth investing in. Also, if the phoen number is open to anyone, I would lvoe to get it for DD (you can PM it if you prefer). We pay a set amount every month to be able to call US landlines as much as we want (good for keeping in contact with grandma). That might be really nice for DD.

Can you maybe order an 8th Grade Algebra book/workbook in English?

agnes!

Thank you. It is a good idea and we looked at several books a couple of months ago but it seems like things are covered in a different order here and we could never find less than three books to cover what she has in her one (and lots of "other" stuff in there she does not have). It may still be something we do later on though.
So far she is okay in everything else (physics, chemistry, German, Spanish--I cannot imagine learning German AND learning Spanish from German all at once, ethics, etc.). She just can't follow the rapid fire talking of this one teacher and the lady almost never writes an example out for the kids We also live in a university town, so if she does start to have too many problems figuring things out on her own I can probably find an English speaking tutor to hire. It just seems silly to hire a tutor now when DD understands the concepts quite quickly once she figures out what she is supposed to be learning and finds an example or two.
I want to thank you all again for your excellent help and suggestions.

 

[dawson5]

I don't know if it's open to everyone but you can always try. This is the blurb in the newsletter:

Starting September 2, Rose-Hulman's Homework Hotline will be available to 6th-12th graders. Students are encouraged to call the Homework Hotline toll free for math and science homework help. Hotline hours are 7:00pm-10:00pm EST, Sunday-Thursday. Toll Free 1-877-275-7673 or www.askrose.org For more information or additional Homework Hotline materials, call 812-877-8319.

Holiday Closing December 18, 2009 thru January 2, 2010

Resume Operation:
January 3, 2010-7:00pm EST