Question

3x+7=x - 15 i dont know how to solve it the answer is -11 but i dont know how to get to that

Answer 1

3x + 7 = x - 15

First, make sure to subtract $x$ from both sides.
$3x + 7 - x = -15$
Second, simplify 3x - x to get 2x, and then keep the 7.
$2x + 7 = -15$
Third, subtract $7$ from both sides. 
$2x = -15 - 7$
Fourth, simplify -15 - 7 to get -22.
$2x = -22$
Fifth, take the 2 and divide both sides by it, keeping the $x$ by itself.
$x = - \frac{22}{2}$
Sixth, since 11 goes into 2 to get 22, simplify the fraction to 11.
$x = -11$

Answer: x = -11