Question

What is the value of x, when 10(x + 2) = 5(x + 8)?

Answer 1

10 (x + 2) = 5 (x + 8)

First, we can start off by dividing each side by 5. Each side usually meaning, the whole number in front of the parentheses, in simpler words. 10 ÷ 5 = 2 and 5 ÷ 5 = 1, which can be represented as a variable (x).
$2(x + 2) = x + 8$

Second, we can now expand our problem. Basically, remove parentheses. We're focusing on the left side of the problem right now, so to expand 2(x + 2), we could combine 2 and the variable to create 2x, and multiply 2 times 2, which equals 4.
$2x + 4 = x + 8$

Third, our next step is to subtract 4 from each side. Now all we are trying to do is get the variable to equal something by itself.
$2x = x + 8 - 4$

Fourth, let's simplify the right side of the problem now. x + 8 - 4, we would start of by subtracting 8 - 4, which equals 4 and leave the variable alone.
$2x = x + 4$

Fifth, subtract the variable (x) from each side. You will get the problem to look like: 2x - x = 4. We can now simplify 2x - x, which equals x.
$x = 4$

Answer: $\fbox {x = 4}$

Answer 2

$\displaystyle 10(x+2)=5(x+8) \\ 10x+20=5x+40 \\ 10x-5x=40-20 \\ 5x=20 \\ x= \frac{20}{5} \\ x=4$