Algebra prob help!!

[irish dancer]

Ok, here is DDs math problem:

A garage charged $248 for parts and $30/h for labor for work on a car. How many hours did the garage spend working on the car if the total bill was $572?


She has to write the Algebraic equation and solve it.


I've given her an answer which she insists is wrong but she doesn't know what it's supposed to be so does anyone know the answer??

TIA

 

[teacherforhi]

248 + 30h = 572

 

[golfgal]

I come up with 2.3 hours but I am really bad at math so it could be WAY off.

248x=30*572 ??

 

[teacups]

248 + 30h = 572

huh?

Oh Im not saying you are wrong! I pretty much knew I sucked at math long before opening this thread anyway.
And that is not the answer I got. LOL!

 

[Nette]

248 + 30h = 572

Yep, except I would have written it: 572-248 = 30h (which would be the first step if you wrote it the way PP did. )

 

[mickeymedic]

h=10.8

 

[Nette]

huh?

Oh Im not saying you are wrong! I pretty much knew I sucked at math long before opening this thread anyway.
And that is not the answer I got. LOL!

572 is the total bill. Minus 248 for parts... the remainder is the labor...

so labor = 572-248
or
30h labor = 572-248

 

[irish dancer]

248 + 30h = 572

h=10.8

Yeah!! That is exactly what I got.

I know it's been a long time since I've done Algebra but I didn't think I'd totally lost it. Although she's only in the 6th grade so I might be in for trouble especially if she gets into Calculus, never could figure that stuff out!

 

[wall*e2008]

248 + 30h = 572

Correct.

The total bill is $572. The cost of parts plus labor equals the total bill. Labor cost $30/hour * number of hours.

Thus

248 + 30h = 572

Subtracting the cost of the parts from each side yields:

248 + 30h - 248 = 572 - 248

30h = 324

Now divide both sides by the hourly rate to get the number of hours

30h/30 = 324/30
h = 10.8 hours of labor

 

[shortbun]

Correct.

The total bill is $572. The cost of parts plus labor equals the total bill. Labor cost $30/hour * number of hours.

Thus

248 + 30h = 572

Subtracting the cost of the parts from each side yields:

248 + 30h - 248 = 572 - 248

30h = 324

Now divide both sides by the hourly rate to get the number of hours

30h/30 = 324/30
h = 10.8 hours of labor

I agree. This is Algebra? I guess because it's solve for an unknown but it's pretty easy Algebra. Isolate the unknown by doing the same thing to both sides. Always do the same thing to each side.

 

[LoraJ]

I'm taking algebra for a collge course now and I swear we had this same problem.


It should be written as:

248 + 30x=572

 

[december]

248 + 30h = 572

I teach Algebra, and this is how I would teach my kids to write it. $248 is the fixed amount, or y-intercept. $30 is the slope, so 30h is the varying amount. To solve the equation, subtract 248 from both sides, then divide by 30 to get 10.8.

 

[Planogirl]

Alright! I still remember my algebra or at least my easy algebra.

 

[jenlynn0808]

what letter you use as the variable. h or x it is the same thing...the unknown quantative. Persoanlly, I always try to avoid x because it can be confused with x(used as a multiplication sign).

 

[MickeyMouseGal]

30x+248=572
30x=572-248
30x=324
30x/30=324/30
x=10.8 (or 10 hours and 48 minutes)

 

[LoraJ]

what letter you use as the variable. h or x it is the same thing...the unknown quantative. Persoanlly, I always try to avoid x because it can be confused with x(used as a multiplication sign).

LOL! We don't even use x for multpiplication in my class. It's either 8*8 or 8(8) or 8.8 (the period would be higher.

And I didn't mean that it HAD to be x, just the way it should be written. We use x all the time though for every word problem, because it has transitioned into graphing equations with x,y.

 

[jenlynn0808]

LOL! We don't even use x for multpiplication in my class. It's either 8*8 or 8(8) or 8.8 (the period would be higher.

And I didn't mean that it HAD to be x, just the way it should be written. We use x all the time though for every word problem, because it has transitioned into graphing equations with x,y.

LOL!! My fourth graders aren't that advance...

 

[Cindy B]

what letter you use as the variable. h or x it is the same thing...the unknown quantative. Persoanlly, I always try to avoid x because it can be confused with x(used as a multiplication sign).

That is why you have the dot or the two numbers next to each other. I like to use x because that is what most texts use.