Question

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

Answer 1

x = 5

Explanation:

Given

f(x) = - 3x + 21 and f(x) = 6, then equating gives

- 3x + 21 = 6 ( subtract 21 from both sides )

- 3x = - 15 ( divide both sides by - 3 )

x = 5