Jika f(2) =5 dan f(5)=8 dengan rumus fungsi f(x)=ax + b,nilai f(10) adalah...

f(x) = ax + b

f(2) = 5
2a + b = 5

f(5) = 8
5a + b = 8

2a + b = 5
5a + b = 8
------------------ -
-3a = -3
a = 1

2a + b = 5
2(1) + b = 5
2 + b = 5
b = 5 - 2
b = 3

f(x) = x + 3

f(10) = 10 + 3 = 13