y-10y+18=-3 (5y-7) +5y
y-10y+18= -15y+21 +5y
-9y+18=-10y+21
-9y+10y= 21-18
y=3
Instructions:
1. Solve the ones in the bracket.
2. Then add/subtract the one with the say value (the ones with y).
3. Put the ones with y on one side and the numbers on the different side.
Note: the positive value/ negative value will always change when u move it to another side.