Question

9b+6b-15=615
Спасибо;)

Answer 1

9b+6b-15=615
15b=615+15
15b=630
b=630÷15
b=42

9×42+6×42-15=615
378+252-15=615
630-15=615
615=615 

Answer 2

9b + 6b - 15 = 615
15b = 615 + 15
15b = 630
b = 630/15
b = 42

Ответ: 42