Question

f(x)=7x+3 and g(x)=-6x-8, find (f•g)(x) and (f•g)(-1)

Answer 1

Answer:

$(f*g)(x)=-42x^2-74x-24$

$(f*g)(-1)=8$

Step-by-step explanation:

$f(x)=7x+3\\ g(x)=-6x-8$

$(f*g)(x)=(7x+3)(-6x-8)\\(f*g)(x)=-42x^2-56x-18x-24\\(f*g)(x)=-42x^2-74x-24$

Now;

$(f*g)(-1)=-42x^2-74x-24\\(f*g)(-1)=-42(-1)^2-74(-1)-24\\(f*g)(-1)=-42(1)+74-24\\(f*g)(-1)=-42+50\\(f*g)(-1)=8$