Question

Решите уравнения
-7(2-3х)=56
И
(5+7а)*15=-30

Answer 1

1) -7(2-3х)=56
-14 + 21x = 56
-14 + 21x -56 = 0
-70 + 21x = 0
21x = 70
x = 70/21 = $\frac{1}{3}$

2) (5+7а)*15=-30
75 + 105a = -30
75 + 30 + 105a = 0
105 + 105a = 0
105a = -105
a = $-\frac{105}{105}$ = -1