Tolong ya di jawab sekarang

17. f(x) = ax + b
f(3) = 3a + b = 7
f(1) = a + b = -1
------------------ -
2a = 8
a = 4

a + b = -1
4 + b = -1
b = -1 -4
b = -5

a = 4
b = -5