rumus fungsi f(x) =ax+b. jika f(5) = 13 dan f(3) =7. tentukan rumus fungsinya!

f(x) = ax + b

f(5) = 5a + b = 13
f(3) = 3a + b = 7
————————— —
2a = 6
a = 6/2
a = 3

3a + b = 7
3.3 + b = 7
9 + b = 7
b = 7 - 9
b = -2

rumus fungsinya → f(x) = 3x + (-2)

f(x) =ax+b
# f(5) = 13
a.5+b=13
5a+b=13...........(1)
#f(3) =7
a.3+b=7
3a+b=7............(2)
#
5a+b=13
3a+b=7
------------------(-)
2a=6
a=6/2
a=3
#3a+b=7
3.(3)+b=7
9+b=7
b=7-9
b=-2
jadi rumus fungsinya f(x) =ax+b adalah
f(x) =3x+(-2)