suatu fungsi f dinyatakan dengan rumus f(×)=ax+b, jika f(3)=17, dan f(-2)=-3 , maka nilai f(5)adalah

f(x) = ax + b

f(3) = a(3) + b = 17
= 3a + b = 17

f(-2) = a(-2) + b = -3
= -2a + b = -3

jadi (3a + b = 17) - (-2a + b = -3)
5a = 20
a = 4
3a + b = 17
3(4) + b = 17
12 + b = 17
b = 17-12
b = 5

f(5) = a(5) + b
= 4(5) + 5
= 20 + 5
= 25