Question

Suatu fungsi di nyatakan dengan rumus f(x)=ax + b . jika f (3) =3 dan f (5) =7 . maka nilai dari f (2) adalah.....

Answer 1

F(x) = ax+b

pers 1
f(3) = 3a + b
3 = 3a + b

pers 2
f(5) = 5a + b
7 = 5a + b

eliminasikan pers 2 dan pers 1
7 = 5a + b
3 = 3a + b  -
4 = 2a
a = 4/2
a = 2

cari b
3 = 3a + b
3 = 3(2) + b
3 = 6 + b
b = 3-6
b = -3

sehingga, f(2)
f(2) = 2a + b
f(2) = 2(2) + -3
f(2) = 4 - 3
f(2) = 1
 

Answer 2

F(x)=ax+b
f(3)=3a+b=3
f(5)=5a+b=7
-------- -
-2a=-4
a=2
5(2)+b=7
b=-3
jadi
f(2)=ax+b
=2(2)-3
=1