g (x) =2x-5 dan (fog) (x) = 4x2-20x+25 nilai f (1) adalah

menentukan nilai f(1)

(fog) (x) = 4x² - 20x + 25
f(g(x)) = 4x² - 20x + 25
f(2x - 5) = 4x² - 20x + 25
f(1) = 4((x + 7) ÷ 2)² - 20((x + 7) ÷ 2) + 25
f(1) = 4((x² + 14x + 49) ÷ 4) - (10x + 70) + 25
f(1) = x² + 14x + 49 - 10x - 70 + 25
f(1) = x² + 4x + 4

Fog (x) = 4x² -20x+25
f (g(x)). = 4 x² -20x+25
f ( 2x-5 ) = 4 (2x-5)² - 20(2x-5) +25
= 4(4x+25) - 40x+100 +25
= 16x + 100 - 40x +100 + 25
= 16x - 40x + 225
= -24x + 225
f(1) = -24(1) + 225
= -24+225
= 201