Brainiest to whoever answers this!! and please

Answer: Number 9: x = 20, Number 10: x = 65
Step-by-step explanation:
Number 9:
3x + 10 = 90 - x
3x + x = 90 - 10
4x = 80
80 / 4
x = 20
Number 10:
2x + 15 = 145
2x + 15 - 15 = 145 - 15
2x = 130
2x / 2 = 130 / 2
x = 65