Basic mathematics

Question

f(x) = 4x + 3 g(x)=5x -4



fg(x) = 20x+p

Find the value of p

Answer 1

Hello Marcell,

It looks like you wrote f(g(x)) = 20 x + p and are trying to find p.

f(g(x)) means f(5x-4). To find it, You will replace any x in f(x) by 5x-4.

f(5x-4) = 4(5x-4) + 3 = 20x - 16 + 3 = 20x -13

From here, you can see that p = -13.