Resposta:

Explicação passo a passo:

A) y+9=3

y = 3 - 9

y = -6

B) 7x+17=10

7x = 10 - 17

7x = -7

x = -7/7

x = -1

C) 5x-40=60

5x = 60 + 40

5x = 100

x = 100/5

x = 20

D) 5x=-90

x = -90/5

x = -18

E) 2x/3=-6

2x = -6 . 3

2x = -18

x = -18/2

x = -9

F) x+1/5=2/5

x = 2/5 - 1/5

x = 1/5

G) 3x+1=19

3x = 19- 1

3x = 18

x = 18/3

x = 6

H) 11-3Y=2

-3y = 2 - 11

-3y = -9 .(-1)

3y = 9

y = 9/3

y = 3