Mohon bantuannya bapak2 dan ibu guru ... Terimakasih

fungsi

23.
f(x) = 2x -1 , 0< x < 1
f(x) = x² + 1, untuk x lainnya

f(2). f(-4) + f(1/2) f(3) =
= (2²+1) {(-4)² +1} + {2(1/2) - 1} {3²+1}
= (5)(17) + (0)(10)
= 85

24.
f(x) = 2x+ 77
g(x)= x² - 4x + 6
(f+g)(x) = 28
2x + 7+ x² - 4x + 6 = 28
x² - 2x +13 - 28 = 0
x² - 2x -15 =0
(x - 5)(x + 3) =0
x = -3  atau x = 5

25.
f(x) = x³ - 1
g(x) =  2x + 5
gof(x) = g{x³-1) = 2 (x³ - 1) + 5
gof(x) = 2x³ - 2 + 5
gof(x)= 2x³ + 3