diketahui f(2x-8)=x²-4x maka f(6)?

langsung aja y

f(2x-8) = x² - 4x

misal :

2x - 8 = a
2x = a + 8
x = a+8 / 2

soal menjadi

f(x) = (a+8 / 2)² - 4(a+8 / 2)
f(x) = (a+8)² / 4 - 2(a+8)
f(x) = a²+ 16a + 64 /4 - 2a - 16
f(x) = (a² + 16a + 64 - 8a - 64) / 4
f(x) = (a² - 8a) / 4

f(x) = (x² - 8x) / 4
f(6) = (6² - 8(6)) / 4
f(6) = (36-48) / 4
f(6) = -12/4
f(6) = -3

semoga berguna +_+

f(2x-8) = x^2-4x
Misal a = 2x-8
2x = a+8
x = a+8 / 2
Langsung
f(a) = x(x-4)
f(a) = (a+8)/2 ((a+8)/2 - 4)
f(a) = (a/2 + 4)(a/2)
f(6) = (3 + 4)3 = 7 x 3 = 21