Question

For what values of x is f(x) = square root of x-4 equal to 4?

Answer 1

Answer:

x = 20

Step-by-step explanation:

given f(x) = $\sqrt{x-4}$, we have to solve

$\sqrt{x-4}$ = 4

Square both sides

($\sqrt{x-4}$)² = 4²

x - 4 = 16 ( add 4 to both sides )

x = 20

As a check

$\sqrt{20-4}$ = $\sqrt{16}$ = 4 ← correct