# [SOLVED] How do I get to answer this problem ?

• February 23rd 2006, 05:45 PM
china_88
[SOLVED] How do I get to answer this problem ?
how do I solve this.... (a+b)squared - (c+d)squared ???

• February 23rd 2006, 06:15 PM
ThePerfectHacker
Quote:

Originally Posted by china_88
how do I solve this.... (a+b)squared - (c+d)squared ???

Remember the diffrence of two squares,
$x^2-y^2=(x+y)(x-y)$
Thus,
$(a+b)^2-(c+d)^2$
Over here $x=a+b,y=c+d$. Thus,
(watch those signs :eek:
$[a+b+(c+d)][(a+b)-(c+d)]$
Thus,
$(a+b+c+d)(a+b-c-d)$.
Q.E.D.