SOLUTION: please help: if f(x)=(5x+B)/(2x-A) and f(2)=0, f(4)=undefined, then find A and B Thanks for any help

Algebra ->  Rational-functions -> SOLUTION: please help: if f(x)=(5x+B)/(2x-A) and f(2)=0, f(4)=undefined, then find A and B Thanks for any help      Log On


   

Question 690058: please help: if f(x)=(5x+B)/(2x-A) and f(2)=0, f(4)=undefined, then find A and B
Thanks for any help
Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
You can put this solution on YOUR website!
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)
%285x%2BB%29%2F%282x-8%29 = 0
x = 2
%285%282%29%2BB%29%2F%282%282%29-8%29 = 0
%2810%2BB%29%2F%28-4%29 = 0
B=-10