Jawabanmu

2014-04-10T19:43:44+07:00
-3a + b = -15
2a + b = 0

Selanjutnya di kurangin, jadi =
 -5a = -15
a = 3 

2(3) + b = 0
6 + b = 0
b = 0

f(-5) = -5(3) + 0 = -15

2014-04-10T19:53:16+07:00
F(-3)=-3a+b=-15
f(2)=2a+b=0
_____________ -
         -5a=-15
            a=-15/-5
            a= 3
-3a+b=-15
-3x3+b=-15
-9+b=-15
b=-15+9
b=-6

f(-5)=-5a+b
     =-5x3+-6
     =-15-6
     =-21
jawabannya sangat rinci . terima kasih banyak
samasama ;)