diketahui f(x)=ax+b jika f(5)=20 dan f(10) =25 maka nilai f (16) adalah ? :)

Bab Relasi dan Fungsi (dengan bumbu SPLDV)

f(10) = 10a + b = 25
f(5) = 5a + b = 20
_______________ -
5a = 5
a = 1

5(1) + b = 20
b = 20 - 5
b = 15

f(x) = x + 15

f(16)
= 16 + 15
= 31

5a + b = 20
10a+b = 25
——————— -
- 5a= -5
a = 1

(5a + b= 20) x 2
(10a+ b= 25) x 1

10a+ 2b= 40
10a+ b = 25
———————— -
b = 15

f(16) = ax + b
f(16) = 1(16) + 15
f(16) = 31