To solve for x, we will begin by using the distributive property
6x - 2(x + 4) = 12
6x - 2x - 8 = 12
(always remember to sort your negatives!)
Add like terms
4x - 8 = 12
Add 8 to both sides
4x = 20
Divide both sides by 4
x = 5
Well there both even numbers so the gcf factor would have to be even also
60 = 1,2,3,4,5,6,10,12,15,20,30,60
72 = 1,2,3,4,6,8,9,12,18,24,36,72
The Gcf would be 12
Remember PEMDAS - parentheses, exponents, multiply, divide, add, subtract
because multiply come before subtract, your first step would be 1/2 x 2 = 1
next, you subtract -> 15 - 1 = 14
14 is your answer
