diketahui f(x) = x² - nx dan g(x) = 2x - 3. jika (fog) (2) = (gof) (-2). tentukan nilai 5n

jawab

fog (2) = (gof)(-2)
f {g(2)} = g{f(-2)}
f(2 . 2 - 3) = g ((-2)² - n(-2))
f(1) = g(4  +2n)
1² - n(1) =2(4+2n) - 3
1 - n = 8 + 4n - 3
1- n = 5+ 4n
- n - 4n = 5 - 1
-5n = 4
n  = -4/5

nilai 5 (n) = 5(-4/5)= - 4

f(x) = x² - nx
g(x) = 2x - 3

(fog)(2) = (gof)(-2)
(2.2 - 3)² - n(2.2 - 3) = 2((-2)² + 2n) - 3
1 - n = 2(4 + 2n) - 3
1 - 5 = 5n
n = -4/5

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5n = -4