what is [fog](x) if f(x)= 2x +7 and g(x)= -3x+4.

Question

my list of possable answers is

a.-6x-17 b.-6x+15 c.-6x+8 and d.-6x-10.

Answer 1

Given functions are f (x ) = 2x + 7 and g (x ) = -3x + 4

[ f o g ](x ) = f (g (x ))

Substitute the expression for functioning g  (in this case -3x + 4 ) for g (x ) in the composition.

= f (-3x + 4)

Now substitute this expression (-3x + 4) in to function f  in place of the x  value.

= 2(-3x + 4)+ 7

= -6x + 8 + 7

= -6x + 15

[ f o g ](x ) = -6x + 15

Option b  is correct choice.