diketahui f(x)=ax+b jika f(5)=13 dan f(-2)=-8 tentukan; rumus fungsi f(x)

f(x) = ax + b

f(5) = 5a + b
13 = 5a + b ...(i)

f(-2) = -2a + b
-8 = -2a + b ... (ii)

Eliminasi (i) dan (ii)
5a + b = 13
-2a + b = -8
----------------- (-)
7a = 21
a = 3

Subtitusikan ke ii
-2(3) + b = -8
b = -8 + 6
b = -2

rumus f(x) = 3x - 2