suatu fungsi dirumuskan f(×) =ax+b jika f(-2)=13 dan f3=-7 maka nilai f(-3) adalah

F(x)=ax+b
F(-2)=-2a+b
13=-2a+b .....1

F(3) =3a+b
-7=3a+b .....2

13=-2a+b
-7=3a+b
---------------- -
20=-5a
-4 = a
b = 5
F(x) = -4x+5
F(-3) = -4.-3 +5
= 12+5
= 17

F(x) = ax+b
F(-2)=a• (-2)+b
13 = -2a+b .... (1)
F(3) = a•3 + b
-7 = 3a+b .... (2)
(1) & (2) di eliminasi
-2a+b = 13
3a+b = -7
--------------- -
-5a = 20
a = 20/-5
a = -4

a subtitusikan ke pers. (2)
3a+b = -7
3•(-4) + b = -7
-12 +b = -7
b = -7 + 12
b = 5
Maka f(-3) = (-4)•(-3) + 5
= 12 + 5
= 17 ✅
Di koreksi lagi ya kalau ada yg salah.....