20 - k/15=17

Answer 1

-k/15 = 17-20
-k/15 = -3
-k = (-3)(15)
-k = -45
k = 45

Answer 2

20 - k / 15 = 17

Subtract 20 to both sides

- k / 15 = - 3

Multiply both sides by - 15

k = 45