Question

se f (x) = x + 1 É g (x) = 2x+3 com x real, determine:
a- f (g (12)
b- g (f (-3)
c- f (g (-5)

Answer 1

f(g(x))= f(2x+3) = 2x + 3 + 1 = 2x + 4
g(f(x)) = g(x+1) = 2(x+1) + 3 = 2x + 2 + 3 = 2x + 5

a)
f(g(x)) = 2x + 4
f(g(12)) = 2.12 + 4
f(g(12)) = 24 + 4 = 28

b) g(f(x)) = 2x + 5
g(f(-3) = 2.(-3) + 5 = -6 + 5 = -1

c) f(g(-5)) = 2(-5) + 4
f(g(-5)) = -10 + 4 = -6

Answer 2

Boa tarde Nicolle

f(x) = x + 1
g(x) = 2x + 3

a) 

f(g(12)) 

g(12) = 2*12 + 3 = 27
f(27) = x + 1 = 27 + 1 = 28

b)

g(f(-3))

f(-3) = -3 + 1 = -2
g(-2) = -2*2 + 3 = -1

c)

f(g(-5))

g(-5) = -2*5 + 3 = -7
f(-7) = -7 + 1 = -6

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