Given that f(x) = 2x + 1 and g(x) = −5x + 2, solve for f(g(x)) when x = 3.

a) -91
b) -33
c) -25
d) 35

Question

Given that f(x) = 2x + 1 and g(x) = −5x + 2, solve for f(g(x)) when x = 3.

a) -91
b) -33
c) -25
d) 35

barrelracing · Answer

@Michele_Laino

anonymous · Answer

First you're gonna do f(g(x)) so you plug in -5x+2 into the x's on the f(x) function $$f(g(x))=2(-5x+2)+1$$
after that you just distribute and you get $$-10x+5$$
now you just plug in x=3 into the equation and solve
$$-10(3)+5$$$$-30+5$$$$=-25$$

michele_laino · Answer

by definition of composite function,, we can write this:
$$f\left( {g\left( x \right)} \right) = 2g\left( x \right) + 1 = 2\left( { - 5x + 2} \right) + 1$$