Question

If f(x)=the square root of x+12 and g(x)=2 times the square root of x, what is the value of (f-g)(144)?

Answer 1

$(f-g)(144) = \sqrt{144}+12-2 \sqrt{144} \\(f-g)(144) = 12+12-2*12 \\ (f-g)(144) = 24-24 \\ (f-g)(144) = 0$

Answer 2

If (f-g)(144) plug 144 for x and g

You get f(x) = f(144) = √144 + 12 = 12 + 12 = 24

g(x) = g(144) = 2√144 = 2*12 = 24

f-g = 24-24 = 0