<PRE><B>Question 690058</B>
if f(x)=(5x+B)/(2x-A) and f(2)=0, f(4)= undefined, then find A and B 
:
Find A first, f(4) undefined, division by 0, so we have
2x - A = 0
x=4
2(4) - A = 0
8 - A = 0
A = 8
:
Replacing A with 8, f(2)
{{{(5x+B)/(2x-8)}}} = 0
x = 2
{{{(5(2)+B)/(2(2)-8)}}} = 0
{{{(10+B)/(-4)}}} = 0
B=-10</PRE>