di ketahui fungsi f(x)=ax+b.jika nilai f(-1)=-5 dan f (3) = 7 tentukan: bantu gan

Kelas 8 Matematika
Bab 2 - Fungsi

f(x) = ax + b

f(-1) = -a + b = -5
f(3) = 3a + b = 7

Eliminasi nilai b
-a + b = -5
3a + b = 7
________ _
-4a = -12
a = -12/-4
a = 3

Substitusikan nilai a
-a + b = -5
-3 + b = -5
b = -5 + 3
b = -2

f(x) = ax + b
f(x) = 3x - 2