10x + 6(x + 8) = 99 - x; =
34 + 2(2x - 9) = 28; =
10(7y - 2) = 120; =

1)

10x + 6(x + 8) = 99 - x

10x + 6x + 48 = 99 - x

16x + 48 = 99 - x

17x = 51

x = 3

ответ: 3.

2)

34 + 2(2x - 9) = 28

34 + 4x - 18 = 28

4x + 16 = 28

4x = 12

x = 3

ответ: 3.

3)

10(7y - 2) = 120

70y - 20 = 120

70y = 140

y = 2

ответ: 2.

Пошаговое объяснение:

1)10x+6x+48=99-x

17x=51

X=3

2)34+4x-18=28

4x=28-16

4x=12

X=3

3)70y-20=120

70y=140

y=2