Fungsi f(x)=2ax+b, jika f(3)=15,Dan f(1)=-1,maka f(5)=

f(x) = 2ax + b

f(3) = 2a(3) + b = 15
f(3) = 6a + b = 15..........(1)
f(1) = 2a(1) + b = -1
f(1) = 2a + b = -1.....(2)
eliminasi (1) (2)
6a + b = 15
2a + b = -1
________-
4a = 16
a= 4
substitusi a = 4 ke persamaan (2)
2a + b = -1
2(4) + b = -1
b = -1 - 8
b = -9
fungsi f(x) = 8x - 9
f(5) = 8(5) - 9 = 40 - 9 = 31