diketahui f(x)=ax+b dengan f(-4)=3 dan f(2)=9 tentykan nilai a dan b kemudian tuliskan fungsinya

f(x) =ax+b
f(-4) = a(-4)+b
3 = -4a+b............ 1

f(2) = a(2) +b
9 = 2a+b...... 2

-4a+b = 3
2a+b=9
---------------- -
-6a = -6
a= 1

2(a) +b =9
2(1)+b= 9
b= 6

a=1,b=6

f(-4) = -4a + b = 3
f(2) = 2a + b = 9
============== --
-6a = -6
a = 1
b = 9-2 = 7

f(x) = x + 7