1. 3x + 7 = 13 (x = - 2; x = 2; x = 5)

3x + 7 = 1 3

3x = 13 - 7

3x = 6

x = 6/3

x = 2

Answer: x=2

Step-by-step explanation:

I am assuming you are asking which x fits the equation. To see if x works for the equation, you would plug it in.

x=-2

3 (-2) + 7=13

-6+7=13

1≠13

x=2

3 (2) + 7=13

6+7=13

13=13

x=5

3 (5) + 7=13

15+7=13

22≠13