26-7·(15-x)=12. 1250:(16+x)=25. 4·(x+36)=6x-14. 3y+(y-2)=2·(2y-1) Решите плз

Question

26-7·(15-x)=12. 1250:(16+x)=25. 4·(x+36)=6x-14. 3y+(y-2)=2·(2y-1) Решите плз

Answer 1

Ответ:

26 - 7 · (15 - x) = 12.

26 - 105 + 7x - 12 = 0

7x - 79 - 12 = 0

7x - 91 = 0

7x = 91

x = 91 : 7

x = 13

1250 : (16 + x) = 25.

1250 = 25 · (16 + x)

1250 = 400 + 25x

25x = 1250 - 400

25x = 850

x = 850 : 25

x = 34

4 · (x + 36) = 6x - 14.

4x + 144 = 6x - 14

6x - 4x = 144 +14

2x = 158

x = 79

3y + (y - 2) = 2 · (2y - 1)

3y + y - 2 = 4y - 2

4y - 4y = - 2 + 2

0 = 0