Question

Given the function f(x) = 3|x – 2| + 6, for what values of x is f(x) = 18?

Answer 1

this can also be explained as c on edg :)

Answer 2

x = - 2, x = 6

Explanation:

Given f(x) = 18 we require to solve

3 | x - 2 | + 6 = 18 ( subtract 6 from both sides )

3 | x - 2 | = 12 ( divide both sides by 3 )

| x - 2 | = 4

The absolute value function always returns a positive value, however, the expression inside can be positive or negative, thus

x - 2 = 4 ( add 2 to both sides )

x = 6

OR

- (x - 2) = 4

- x + 2 = 4 ( subtract 2 from both sides )

- x = 2 ( multiply both sides by - 1 )

x = - 2

As a check substitute these values into the left side of the equation and if equal to the right side then they are the solutions

x = 6 → 3|6 - 2| + 6 = 3|4| + 6 = 3(4) + 6 = 12 + 6 = 18 ← True

x = - 2 → 3|- 2 - 2| + 6 = 3|-4| + 6 = 3(4) + 6 = 12 + 6 = 18 ← True

Hence solutions are x = - 2, x = 6