diket=f(x)=px+q jika f(-3)=12 dan f(4)=26 maka nilai p+2q adalah

Jawab :

f(x) = px + q
f(-3) = p(-3) + q = -3p + q = 12
f(4) = p(4) + q = 4p + q = 26

-3p + q = 12
4p + q = 26
__________ - 
-7p = -14
   p = 2

4p + q = 26
4(2) + q = 26
8 + q = 26
       q = 26 - 8
       q = 18

f(x) = px + q = 2x + 18 

Nilai p + 2q
= 2 + 2 × 18
= 38