Respuesta :

Answer:

x = 7

Hope this helps :)

Explanation and Check part below.

Step-by-step explanation:

1. Isolate variable by doing the inverse operation which is in this case subtracting 9 on both sides of the equation.

3x + 9 = 30

- 9 - 9

3x = 21

2. Divide both sides of the equation by 3 since this is the inverse operation.

3x = 21

--- ---- <-------- fraction bar, divide

3 3

x = 7

Check:

3(7) + 9 = 30

21 + 9 = 30

30 = 30 ✓