Question

Diketahui f(×)=ax+b. jika f(4)=-2, f(-4)=6 maka nilai f(-5) adalah

Answer 1

F(x) = ax+b
f(4) = 4a + b = -2
f (-4) = -4a+b = 6
di eleminasi
4a+b = -2
-4a+b = 6   
8a = -8
a = -1 ---> b = 2

nilai f(-5) = -5a + b
               = (-5 x -1) + 2
               = 7

Answer 2

F(4) = 4a+b =-2 F(-4) = -4a + b = 6 Jadi, di eliminasi 4a+b=-2 -4a+b=6 2b=4 -> b=2 Subs -> 4a+b=-2 4a+2=-2 4a=-2-2 4a=-4 a=-1 Maka, f(-5) = ax+b = -1x-5+2 =5+2 =7