diketahui fx=ax + b f(-1)=7 dan f(3)=-5 nilai f(-6) adalah

f(x) : ax + b
f(-1) : -a+b = 7 ... pers 1
f(3) : 3a+b = -5 .... pers 2
cari a dulu
eliminasi b dengan pers 1 dan pers 2
-a-3a = 7-(-5)
-4a = 12
a = -3

Subtitusi ke pers 1
3+b=7
b =4
f(-6) : -3(-6) + 4
: 18 + 4 : 22

f(x) : ax+b

f(-1) : -1a + b = 7
f(3) : 3a + b = -5
_____________-
-4a = 12
a = 12/-4 = -3

3a + b = -5
3(-3) + b = -5
-9 + b = -5
b = -5 + 9 = 4

f(-6) = -6a + b
= -6(-3) + 4
= 18 + 4 = 22