Question

Уравнение 9 × x - 15 = 90 - 42

Answer 1

9*x=63. x=7..........

Answer 2

9х-15=90-42
9х-15=48
9х=48+15
9х=63
х=63:9
х=7
Проверка
9*7-15=90-42
63-15=48
      48=48