diketahui rumus f(x)=ax+b. jika f(2)=-8 dan f(5)=14, maka nilai a dan b berturut-turut adalah... . . . . tolong jawab gaes sekalian caranya juga ya..

f(x) = ax+b
f(2) = -8
f(5) = 14

f(2) = a(2)+b
-8 = 2a+b...............(1)
f(5) = a(5)+b
14 = 5a+b...............(2)

5a+b = 14..................(2)
2a+b = -8..................(1)
_________________ _
3a = 22
a = 22/3

2a+b = -8
2(22/3) + b = -8
44/3 + b = -8
b = -8 - 44/3
b = -68/3