Answer:
x = 7
Hope this helps :)
Explanation and Check part below.
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 ✓