Question

Which ordered pairs lie on the graph of the exponential function f(x)=2(x+4)−8f(x)=2(x+4)−8 ?

Answer 1

Simplify the equation
f(x) = 2x + 8 - 8
f(x) = 2x

Now substitute the x values 
f(24) = 2(24) = 48 
f(8) = 2(8) = 16
f(2) = 2(2) = 4
f(-2) = 2(-2) = -4

The correct answer is 4. (-2,-4)

Answer 2

I assume this is meant to read f(x)=2(x+4)-8, which is f(x)=2x. The only point to satisfy this is (-2,-4), answer 4.