Question

Fungsi f dinyatakan dengan rumus f(x) = px + q. jika diketahiu f (-2) = 3 serta f (2) = 21 tentukan:
a. nilai p dan q
b. f (5) dan f (10)
c. nilai a jika f (a) = 9

Answer 1

F(x) = px + q
f(-2) = -2p + q = 3
f(2) = 2p + q = 21
----------------------(+)
2q = 24
q = 12
f(-2) = -2p + q = 3
-2p + 12 = 3
-2p = 3 - 12
p = -9/-2 = 9/2
f(x) = 9/2 x + 12
f(5) = 9/2 . 5 + 12 = 45/2 + 12 = 34½
f(10) = 9/2 . 10 + 12 = 45 + 12 = 57
f(a) = 9/2 a + 12 = 9
------------------------(×2)
9a + 24 = 18
9a = 18 - 24 = 6
a = 6/9 = ⅔