Math Wizards ...... Help !!

[swanmom]

Now, you're really going to have to be up for a challenge. I'm hoping some Algebra teachers or wizards are here! This is one problem from my DD's homework tonight. I'm trying to help her .........but I can't explain it to her if I can't solve it myself. Don't worry. I'm not going to give her the answer. I just need to see what is the correct solution because if I can see it then I can help guide her. BTW, I've already spent over an hour trying to do this myself! PLEASE HELP!

3[2(x-2) -7(2x + 3)] - 5[4(2x + 5) - (3x -2)] = 6(x + 1) + 1

 

[Beth76]

The only thing I can help with is give you the order of operations PEMDAS
1)Parentheses
2)Exponents
3)Multiply
4)Divide
5)Addition
6)Subtraction

 

[swanmom]

Thanks, Beth. Unfortunately, the problem is so complex that the order of operations isn't enough.............I've worked the problem about 20 times -trying to follow the order of operations and getting a different (wrong) answer each time.

 

[caitycaity]

it's been along time since i have done this, but i think this is how:

3[2(x-2) -7(2x + 3)] - 5[4(2x + 5) - (3x -2)] = 6(x + 1) + 1
3[2x-4-14x-21]-5[8x+20 -3x-2]=6x+6+1
3[-12x-25]-5[5x+18]=6x+7
-36x-75-25x-90=6x+7
-61x-165=6x+7
-61x=6x+172
-67x=172
x= -2.567164179

i'm not certain though, so hopefully someone who is will post!

 

[Beth76]

I decided to give it whirl too after getting over my initial laughing fit. I eventually came up with -91x+141=6x+7 which I'm sure is not correct and even so I got stuck there. I can't remember what to do with the opposite sides of the = sign.

 

[UP Disney]

I decided to give it whirl too after getting over my initial laughing fit. I eventually came up with -91x+141=6x+7 which I'm sure is not correct and even so I got stuck there. I can't remember what to do with the opposite sides of the = sign.

With the opposite sides of the equal sign, you add or subtract one or the other from both sides so that the x's are on one side and the # is on the other.

For example:

-91x+141 = 6x + 7

so add 91x to both sides and subtract 7 from both sides for

141-7 = 6x +91x

134 = 97x

then you'd divide by 97 to get the x alone.

1.38 = x

However, I don't think you had the right equation at this point. I'm verifying my math but I got something close to the answer given.

 

[Bob Slydell]

it's been along time since i have done this, but i think this is how:

3[2(x-2) -7(2x + 3)] - 5[4(2x + 5) - (3x -2)] = 6(x + 1) + 1
3[2x-4-14x-21]-5[8x+20 -3x-2]=6x+6+1
3[-12x-25]-5[5x+18]=6x+7
-36x-75-25x-90=6x+7
-61x-165=6x+7
-61x=6x+172
-67x=172
x= -2.567164179

i'm not certain though, so hopefully someone who is will post!

Never mind -- I was wrong

 

[UP Disney]

it's been along time since i have done this, but i think this is how:

3[2(x-2) -7(2x + 3)] - 5[4(2x + 5) - (3x -2)] = 6(x + 1) + 1
3[2x-4-14x-21]-5[8x+20 -3x-2]=6x+6+1
3[-12x-25]-5[5x+18]=6x+7
-36x-75-25x-90=6x+7
-61x-165=6x+7
-61x=6x+172
-67x=172
x= -2.567164179

i'm not certain though, so hopefully someone who is will post!

In the second line that would be a -3x +2 (not a -2). I'm trying to check my math so that I can post mine all the way through. I got a number close to yours so I'm trying to see where we differed.

 

[caitycaity]

In the second line that would be a -3x +2 (not a -2).

oh yes - you are right!

i was always good at remembering the process, but always make little errors like that! i have a statistics midterm on monday where we have to do hand calculations of regression equations and i just know i am going to make some dumb mistakes!

 

[hiwaygal]

I think caitycaity is close...I've changed a few things (in red)

it's been along time since i have done this, but i think this is how:

3[2(x-2) -7(2x + 3)] - 5[4(2x + 5) - (3x -2)] = 6(x + 1) + 1
3[2x-4-14x-21]-5[8x+20 -3x+2]=6x+6+1
3[-12x-25]-5[5x+22]=6x+7
-36x-75-25x-110=6x+7
-61x-185=6x+7
-61x=6x+192
-67x=192
x= -2.86567...

i'm not certain though, so hopefully someone who is will post!

 

[salmoneous]

it's been along time since i have done this, but i think this is how:

3[2(x-2) -7(2x + 3)] - 5[4(2x + 5) - (3x -2)] = 6(x + 1) + 1
3[2x-4-14x-21]-5[8x+20 -3x+2=6x+6+1
3[-12x-25]-5[5x+22]=6x+7
-36x-75-25x-110=6x+7
-61x-185=6x+7
-61x=6x+192
-67x=192
x= -2.8656716
i'm not certain though, so hopefully someone who is will post!

I see a slight error in your calcs, corrected above. Now I'm just waiting for somebody to find mine.

 

[hiwaygal]

I see a slight error in your calcs, corrected above. Now I'm just waiting for somebody to find mine.

we are just too darn good!

 

[UP Disney]

I think caitycaity is close...I've changed a few things (in red)

I got a +2.86567 so I think you missed one step.

ETA: Nope, it looks like I missed a step. I got a -2.86567...

 

[UP Disney]

Now the only way to know for sure is to go back and place the 2.86... in place of the x and run the calculations to see if it is correct.

 

[debster812]

I am so thoroughly HOSED when DS gets into the upper grades.

As it is, we've had to call my retired MATH teacher mother for homework help 3x already this year, and he's only in 4th grade.

To all of you that even took a STAB at this equation, you are much better DISers than I am.

Good Luck!!

 

[lovesmurfs]

it's been along time since i have done this, but i think this is how:

3[2(x-2) -7(2x + 3)] - 5[4(2x + 5) - (3x -2)] = 6(x + 1) + 1
3[2x-4-14x-21]-5[8x+20 -3x-2]=6x+6+1
3[-12x-25]-5[5x+18]=6x+7
-36x-75-25x-90=6x+7
-61x-165=6x+7
-61x=6x+172
-67x=172
x= -2.567164179

i'm not certain though, so hopefully someone who is will post!

Just weighing in....

3[2(x-2) -7(2x + 3)] - 5[4(2x + 5) - (3x -2)] = 6(x + 1) + 1
3[2x-4-14x-21]-5[8x+20 -3x+2]=6x+6+1 (the - in front of the (3x-2) is like a -1 multiplying through)
3[-12x-25]-5[5x+22]=6x+7
-36x-75-25x-110=6x+7
-61x-185=6x+7
-61x=6x+192
-67x=192
x= -2.8657

 

[Apothecary]

it's been along time since i have done this, but i think this is how:

3[2(x-2) -7(2x + 3)] - 5[4(2x + 5) - (3x -2)] = 6(x + 1) + 1
3[2x-4-14x-21]-5[8x+20 -3x-2]=6x+6+1
3[-12x-25]-5[5x+18]=6x+7
-36x-75-25x-90=6x+7
-61x-165=6x+7
-61x=6x+172
-67x=172
x= -2.567164179

i'm not certain though, so hopefully someone who is will post!

Man, that hurt my brain!! But I got the same answer as you, caitycaity.

 

[UP Disney]

That was fun! I love algebra. I forgot how much fun it can be. Thanks for posting so that I could practice!

 

[shirleyb]

I love algebra -- ok how sick does that make me?

 

[UP Disney]

Probably as sad as I am when I listen to creative people. I am so jealous. I can't play an instrument, my drawings suck, and even to scrapbook is like drawing blood from a turnip. I guess we all have to have something we are good at.