Question

Fungsi f ditentukan dengan rumus f(x) = px + q. Jika f(5) = 10 dan f(-2) = -11, maka nilai p + q adalah

Answer 1

F(x) = px+q F(5) = 5p+q=10 F(-2) = -2p+q=-11 ____________- 7p = 21 P = 3 5p+q=10 5.3+q=10 Q=5 P+q = 3+5 = 8

Answer 2

F(x) = px + q
f(5) = p(5) + q = 10
10 = 5p + q
10 - 5p = q .............. (persamaan 1)
f(-2) = p(-2) + q = -11
-11 = -2p + q ........... (persamaan 2)

-2p + q = -11
-2p + (10 - 5p) = -11
-2p + 10 - 5p = -11
-2p - 5p = -11 - 10
-7p = -21
7p = 21
p = 21/7
p = 3

q = 10 - 5p
q = 10 - 5(3)
q = 10 - 15
q = -5

p + q = 3 + (-5)
= 3 - 5
= -2