diketahui fungsi f (x)=ax+ jika f (2)=-2 Dan f(3)=13 tentukan nilai f (4)........

f(x) = ax + b
f(2) = -2
f(3) = 13

f(2) = 2a + b = -2
f(3) = 3a + b = 13
eliminasi
2a + b = -2
3a + b = 13
_________-
- a = -15
a = 15
substitusi a = 15 ke 2a + b = -2
2(15) + b = -2
30 + b = -2
b = -2 - 30
b = -32
fungsi f(x) = 15x - 32

f(4) = 15(4) - 32 = 60 - 32 = 28