suatu fungsi ditentukan dengan rumus f(x)= px + q jika f(-2)= 17 dan f(5) =-32, maka f(f12)

jawab

f(x)= px + q

f(-2) = 17
f(5)= - 32......(-)

(-2 - 5) p = 17 +32
-7p = 49
p = - 7

f(-2) = 17
q= 17 +2p
q = 17 +2(-7)
q = 3
f(x)= px + q
f(x) = -7x + 3

f ( f (12)) = f ( -7(12) + 3) = f (-81)
f ( f (12)) = -7(-81) + 3 = 570

f (x)= px+q

f (-2)= 17
-2p+q =17

f (5) = -32
5p+q = -32

-2p+q = 17
5p+q = -32
(dielimiansi dengan mengurangkan (-))
-7p = 49
p= -7

-2p + q = 17
-2 (-7)+ q =17
14+q = 17
q = 3

rumus nya menjadi f (x) = -7x + 3
f (12) = -7 (12) + 3
= -84 +3
= -81