fungsi f(x)=ax+b.jikaf(3)=5dan f(1)=-1.tentukanlah.a.nilai a dan b.b.rumus fungsi tersebut

f(x) = ax + b
f(3) = 3a + b = 5
f(1) = a + b = - 1
----------------------(-)
2a = 6
a = 3

a + b = - 1
3 + b = - 1
b = - 1 - 3
b = - 4

f(x) = ax + b
f(x) = 3x - 4