Suatu fungsi f(x) = ax + b dengan f(-1) = -8 , f(1) = -6 , Tentukan : a) Bayangan -2 oleh fungsi f b) nilai x , jika f(x) = -5

Jawab : 

1) Bayangan -2

f(x) = x - 7
= -2 - 7
f(x) = -9

2) x = ... ? 
f(x) = -5
f(x) = x - 7
x - 7 = -5
x = -5 + 7
x = 2

f(x) = ax+b
f(-1)=-8=>a.-1+b=8=>-1a+b=8
f(1)=-6=>a.1+b=6=>1a+b=6
-1a+b-1a+b= -2a
8-6=2
-2a=2
•a=-1

1a+b=6
1.-1+b=6
-1+b=6
•b=6-(-1)=7

a) f(x) = ax+b
f(-2) = -1.-2+7=9

b) f(x) =5
-1x+7=5
-1x= 5-7=-3
x= -3÷(-1)
x=3
*MAAF KALAU SALAH