5*(y-1)-3*(y-2)=7-y+3

Question

5*(y-1)-3*(y-2)=7-y+3

Answer 1

5×(y-1)-3×(y-2)=7-y+3
(5y-5)-(3y-6)=7-y+3
5y - 5 - 3y + 6 = 10 - y 
2y + 1 = 10 - y
2y + y = 10 - 1
3y = 9
y = 9:3
y=3
Проверка
5×(3-1)-3×(3-2)=7-3+3
5×(2)-3×(1)=7
10-3=7
     7=7