Jika f(2)=-1 dan f(-1)=10 dengan rumus fungsi f(x)=ax+b nilai f(12) adalah

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

f(-1)= 10
=> a(-1)+b= 10
=> -a+b= 10

2a+b= -1
-a+b= 10
--------------- --
3a= 9
a= 9÷3
a= 3

2a+b= -1
2(3)+b= -1
6+b= -1
b= -1-6
b= -7

f(x)= 3x-7
f(12)= 3(12)-7
f(12)= 36-7
f(12)= 29