I have no idea how to do this. I found the answer but now I have to explain it.

You have 3 + 2 + 2 which is the same as 7 on the other side.

Step-by-step explanation:

3 + 2 + 2 is 7

x=2

Step-by-step explanation:

3+x+x=7

2x=4

x=2

2nd one in the first row is correct

step-by-step explanation:

y = | -2(-2) |     →     y = | 4 |     →     y = 4       ⇒   (-2, 4)

y = | -2(-1) |     →     y = | 2 |     →       y =   2       ⇒   (-1, 2)    

y = | -2(0) |     →     y = | 0 |     →       y = 0         ⇒   (0, 0)

y = | -2(1) |   c →     y = | -2 |     →     y =   2         ⇒   (1, 2)    

y = | -2(2) |     →     y = | - 4 |     →     y =   4         ⇒   (2, 4)