Pls help solve it like this

1. 4x=124
Divide both sides of equal sign by 4
x=31
3. 34+x=14
Subtract 34 on both sides of equal sign
x= -20
5. -10v=-400
Divide both sides of equal sign by -10
v= 40
7. x-16=-20
Add 16 to both sides of equal sign
x=-4
9. x+8=-4
Subtract 8 on both sides of equal sign
x=-12
11. 17+u =15
Subtract 17 on both sides of equal sign
u = -2