Question

10y - 5 (1 + y ) = 3 (2y - 2) - 20

Answer 1

10y - 5.1 - 5y = 3.2y - 3.2 - 20

10y - 5 - 5y = 6y - 6 - 20

5y - 5 = 6y - 26

5y - 6y = -26 + 5

-1y = -21

y = -21/-1

y=+21

Answer 2

$10y -5(1+y)=3(2y-2)-20\\10y-5-5y=6y-6-20\\5y-5=6y-26\\5y-6y=-26+5\\-y=-21\:\times(-1)\\\boxed{y=21}$

Resposta: y = 21