Algebra: solving w/ 3 variables: 12x - 36 + 2x = -2(2 + x)

[Ruth Perez]

I have been working on equations with multiple variables. I have been doing ok with 2 diffrent variables in one problem but now I am stuck because now it has 3 variables in one problem Can someone help me. Here is the problem:

12x - 36 + 2x = -2(2 + x)

 

[daon]

You said there were three variables. What you actually have is one variable occuring three times.

Simplify Right-hand side:
12x- 36+2x= -2*2 + -2*x
12x- 36+2x= -4 + -2x

Simplify Left-hand side:
12x- 36+2x= -4 + -2x
12x+2x - 36= -4 + -2x ("commute" or switch the -36 and +2x)
14x-36=-4x-2x

Now, add 2x to both sides (you want to get all the x's on the same side) and simplify as much as possible:
14x-36 + 2x=-4-2x+2x
14x-36+2x = -4 (since -2x+2x=0)
14x+2x-36 = -4 (commute the 2x and -36)
16x-36=-4 (add 14x and 2x)
16x-36+36=-4+36 (add 36 to both sides)
16x=32 (by adding like-terms)

Now you need to divide by 16:
\(\displaystyle \L \frac{16x}{16}=\frac{32}{16}\)
\(\displaystyle \L \frac{\not{16}x}{\not{16}}=\frac{\not{32}^2}{\not{16}^1}\)
\(\displaystyle \frac{x}{1}=\frac{2}{1}\)
\(\displaystyle x=2\)

Hope that helps,
-daon

 

[Denis]

Re: Algebra help

12x- 36+2x= -2(2 + x)

complete right side:
12x - 36 + 2x = -4 - 2x
Get the x's on left, numbers on right:
12x + 2x + 2x = -4 + 36
Finish off:
16x = 32
x = 2 : kapish? If not, talk to your teacher...