jika f(x)=2x-5, g(x)=3x+1, dan h(x)=3x²-15 tentukan a. (f°g)(x) b. (f°g)(4) c. (g°f)(x)

jawab

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

a. fog(x) = f {g(x)}= f {3x+1}
= 2(3x  + 1) - 5
= 6x  +2   - 5
= 6x - 3

b.  fog(4) = 6(4) - 3 = 21

c. gof(x) = g { f(x)}
= g {2x - 5)
= 3(2x - 5)  + 1
= 6x - 15 + 1
= 6x - 14