Question

Tolong ya.....
suatu fungsi dirumuskan = 3ax - b/2 . Jika f(3)=-11 , dan f(-1)=1 , maka berapa nilai 3ab?

Answer 1

A = -4/3
b = -2

3a3 - b/2 = -11
3a-1 - b/2 =1
eliminasi

Answer 2

f(x)= 3ax - b/2
f(3)=3.a.3-b/2=-11
     =9a-b/2=-11
    = 18a/2-b/2=-11
   =18a-b=-22 (i)
f(-1)=3.a.-1-b/2=1
     =-3a-b/2=1
     =-6a-b=2 (ii)
(i)18a-b=-22--------------->18a-b=-22
(ii)-6a-b=2 (ii)dikali 3 -->-18a-3b=6
-------------------------------->-4b=-16, b=4
a=(-22+4):18=-1
3ab=3(-1)(4)=-12 :)