Question

F(x)=-3x+21,find x when f(x)=6

Answer 1

x=5

Explanation:

F(x)=-3x+21,

f(x)=6 = -3x+21

6 = -3x+21

Subtract 21 from each side

6-21 = -3x+21-21

-15 = -3x

Divide each side by -3

-15/-3 = -3x/-3

5 = x