45+(71-b*9)=80 Уравнение

Question

45+(71-b*9)=80 Уравнение

Answer 1

45+(71-b*9)=80
71-9ь=80-45
71-9ь=35
9ь=71-35
9ь=36
ь=36:9
ь=4

Answer 2

71-b*9=80-45
71-b*9=35
b*9=71-35
b*9=36
b=36/9
b=4
ответ=b=4