Question

X+7=-3x+40

2x-10=-3x+40

12x-144=9x+9

Answer 1

a)
x+3×=40-7
4×=33
×=33/4
×=8,25

b)
2×+3x=40+10
5×=50
×=50/5
×=10

c)
12×-9×=9+144
3×=153
x=153/3
×=51


espero ter ajudado