Question

Решите уравнения 
1) 2х= 43(х+15)
2) 23(10-х)=-12
3) -14(5х-7)=6
 Ребята вот этим знаком я обозначила дробь

Answer 1

1) 2х = 4/3 * (х + 15)                      2) 2/3 * (10 - х) = - 12

2х = 4/3х + 4/3*15                          2/3*10 - 2/3х = - 12

2х - 1 1/3х = 20                               20/3 + 12 = 2/3х

2/3х = 20                                         18 2/3 = 2/3х

х = 20 : 2/3 = 20 * 3/2                     х = 56/3 : 2/3 = 56/3 * 3/2

х = 60/2 = 30                                  х = 168/6 = 28

3) - 1/4 * (5х - 7) = 6

- 1/4*5х - 1/4 * (- 7) = 6

- 5/4х + 7/4= 6 

- 1,25х = 6 - 1,75

- 1,25х = 4,25

х = 4,25 : (-1,25)

х = - 3,4