Question

Dadas as funções f(x) = 3x+4 e g(x) = 2x-1. Calcule x de modo que g(f(x)) = f (g(2))

Answer 1

f(g(x)) = 3g(x) + 4

f(g(x)) = 3*(2x-1) + 4

f(g(2)) = 3(2*2-1)+4

f(g(2)) = 3(3)+4

f(g(2)) = 13
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g(f(x)) = f(g(2))


2(3x+4)-1 = 13

12x +8 -1 = 13

12x +7 = 13

12x = 13-7

12x= 6

x =6/12

x =1/2

Answer 2

g(f(x)) = f (g(2))
2(3x+4)-1=3(2x2-1)
6x+8-1=12-3
6x+7=9
6x=9-7
x=2/6
x= 1/3