Question

36 - 7x = 120 и 5b + 9x = 21

Answer 1

Пошаговое объяснение:

1) 36-7х=120

-7х=120-36

-7х=84

х=-12

2) 5b+9x=21

5b=21-9x

$b = \frac{21}{5} - \frac{9}{5}x \\ b = - \frac{9}{5}x + \frac{21}{5}$