K (x) = 1/3 (x+9) and k (x) = -4, so x=?

Question

Mathematics

Thalia Crosby

30 April, 15:22

K (x) = 1/3 (x+9) and k (x) = -4, so x=?

+2

Answers (2)

Know the Answer?

Quinten · Answer 1

x = - 21

Step-by-step explanation:

k (x) = 1/3 (x+9) and k (x) = -4

Set them equal

1/3 (x+9) = -4

Multiply each side by 3

3*1/3 (x+9) = -4*3

x+9 = - 12

Subtract 9 from each side

x+9-9 = - 12-9

x = - 21

Roger Orozco · Answer 2

x = - 21

Step-by-step explanation:

if k (x) = - 4 you can substitute that into the original equation:

-4=1/3 (x+9)

multiply both sides of the equation by 3

-12=x+9

subtract 9 from each side

-21=x