1 . diketahui = f (x) = 2x+1 dan g(x)=3x+5 tentukan a .(fog) x. b. (gof) x 2. diket = f(x)=2x+1. dan g(x)=6x²+4x+7 tentukan = a. (gof). (x) b. (gof

1) f (x) = 2x +1 dan g(x) = 3x +5
a) fog(x) = f { g(x) }
= f (3x+5)
= 2(3x +5) +1
= 6x + 10 + 1
= 6x +11
b) gof (x) = g { f (x) }
= g (2x +1)
= 3(2x +1) '5
= 6x +3 +5
= 6x +8
2) f (x) = 2x + 1 dan g (x) = 6x^2+ 4x +7
a) gof (x) = g { f (x) }
= g (2x+1)
= 6(2x+1)^2 +4(2x +1) +7
= 24x^2 + 24x +6 + 8x + 4 +7
= 24x^2 + 32x +17
b) gof (2) = 24(2)^2 + 32(2) + 17
= 96 + 64 + 17
= 177
3) f(x) = (5x +2)/(3x -4)
y = (5x +2)/(3x -4)
(3x -4)y = 5x +2
3xy -4y = 5x + 2
3xy -5x = 4y +2
(3y -5)x = 4y +2
x = (4y +2)/(3y -5)
f-1(x) = (4x +2)/(3x -5)
b) f-1(3) = (4.3 +2)/(3.3 -5)
= (12+2)/(9-5)
= 14/4
= 7/2
= 3 1/2