SOLUTION: given that f(x)=3x-5 and g(x)=3-7x, find a.) (f)(g)(-2) b.) (g)(f)(x) C.) f(f)(x)

Algebra ->  Rational-functions -> SOLUTION: given that f(x)=3x-5 and g(x)=3-7x, find a.) (f)(g)(-2) b.) (g)(f)(x) C.) f(f)(x)      Log On


   

Question 79381: given that f(x)=3x-5 and g(x)=3-7x, find
a.) (f)(g)(-2)
b.) (g)(f)(x)
C.) f(f)(x)
Answer by tutorcecilia(2152) About Me  (Show Source):
You can put this solution on YOUR website!
given that f(x)=3x-5 and g(x)=3-7x, find
a.) f(g(-2))=3(3-7x)-5 [dump g(x) into f(x)]
f(g(-2))=3[3-7(-2]-5 [substitute (-2) for x and solve]
f(g(-2))=3(3+14)-5
f(g(-2))=3(17)-5
f(g(-2))=46
.
b.) (g)(f)(x) =g(f(x))
g(f(x))=3-7(3x-5) [dump f(x) into g(x)]
g(f(x))=3-21x+35
g(f(x))38-21x
.
C.) f(f)(x)=f(f(x))
f(f(x))=3(3x-5)-5 [dump f(x) into f(x)
f(f(x))=9x-15-5
f(f(x))=9x-20