jelaskan cara menentukan rumus fungsi jika diketahui fungsi f dinyatakan oleh f(x)=ax+b dengan f(-1)=2 dan f(2)=11

•f(-1) = 2
f(x) =ax + b
f(-1) = a(-1) + b
2 = a(-1) + b
2= -a + b
•f(2) = 11
f(x) = ax + b
f(2) = a(2) + b
11 = 2a+ b

maaf kalau salah^^

f(x) = ax + b

f(-1) = a(-1) + b
f(-1) = -a + b
-a + b = 2

f(2) = a(2) + b
f(2) = 2a + b
2a + b = 11

Eliminasikan
-a + b = 2
2a + b = 11
----------------- -
-3a = -9
a = (-9) / (-3)
a = 3

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

Rumus fungsi :
f(x) = ax + b
a = 3
b = 5

maka
f(x) = 3x + 5