f(x)=a+b memiliki nilai f(-1)=1&f(2)=13 nilai f (11) adalah

f(x) = ax + b
f(-1) = 1
f(2) = 13

f(-1) = -a + b = 1
f(2) = 2a + b = 13

Eliminasi

-a + b = 1
2a + b = 13
_________-
-3a = -12
-a = -4
a = 4

Disubstitusikan

f(-1) = 4(-1) + b = 1
-4 + b = 1
b = 1+4
b = 5

f(11) = 4(11) + 5
= 44 + 5
= 49