Tolong bantu jawab yg no 11 dong hehe

fog(x) = 4x² + 8x - 3
f(2x+4) = (2x+4)² - 8x - 19
f(2x+4) = (2x+4)² - 4(2x+4) - 3
f(x) = x² - 4x - 3
atau cara lain
f(2x+4) = 4x² + 8x - 3
misalka p = 2x + 4
p - 4 = 2x
2x = p - 4
x = (p - 4)/2
f(p) = 4(p-4 / 2)² + 8(p-4 / 2) - 3
f(p) = 4((p²-8p+16)/4) + 4(p-4) - 3
f(p) = p² - 8p + 16 + 4p - 16 - 3
f(p) = p² - 4p - 3
f(x) = x² - 4x - 3
sama fungsinya
f(-2) = (-2)² - 4(-2) - 3
= 4 + 8 - 3
= 9