19(y-9)=3(y+7) решите с проверкой

Question

19(y-9)=3(y+7) решите с проверкой

Answer 1

19y-171=3y+21
19y-3y=21+171
16y=192y
 y=192/16y=12
ПРОВЕРКА:19(12-9)=3(12+7)=228-171=36+21
57=57