Question

Dados F(x) = 2x+3 e G(x) = 5x-1 determine:
A. g(f(-1))
B. f(g(-1))
C. f(f(0))
D. g(g(g(2)))

Answer 1

f(x) = 2x+3 e g(x)=5x-1

A. g(f(-1))
f(x) = 2x+3
f(-1) = 2(-1)+3
f(-1)= -2 + 3
f(-1)= 1 
Daí vamos para g(f(-1))= g(1) e com g(x)=5x-1

g(x)=5x-1 
g(1)=5.1-1
g(1)= 5-1 
g(1)= 4 

B. f(g(-1))

g(x)=5x-1
g(-1)= 5.(-1)-1
g(-1)= -5-1
g(-1)= -6

f(g(-1))= f(-6)
f(-6)=2x+3
f(-6)= 2.(-6)+3
f(-6)= -12+3
f(-6)=-9

C. f(f(0))

f(0)= 2x+3
f(0)= 2.0+3
f(0)= 3

f(f(0))= f(0)

f(0)= 2x+3
f(0)= 2.0+3
f(0)= 3

D. g(g(g(2)))

g(x)=5x-1
g(2) = 5.2-1
g(2)=10-1 
g(2)= 9

g(g(9))
g(x)=5x-1
g(9)= 5.9-1
g(9)= 45-1
g(9)= 44

g(g(44))
g(x)=5x-1
g(44)= 5.44-1
g(44)= 220-1
g(44)= 219