Try your problem with http://www.montereyinstitute.org/courses/DevelopmentalMath/TEXTGROUP-1-19_RESOURCE/U11_L1_T2_text_container.html and http://www.regentsprep.org/regents/math/algebra/av6/Lfactps.htm and although I do not recommend it, if you really can't figure it out, go here http://www.quickmath.com/webMathematica3/quickmath/algebra/simplify/basic.jsp