decompose some polynomials [ In first, I say "I'm sorry!", because I am not a Englishman and I don't know your language terms very well. ]
OK, I have some polynomials (like $a^2 +2ab +b^2$ ). And I can't decompress these (for example $a^2 +2ab +b^2 = (a+b)^2$).
Can you help me? (if you can, please write the name or formula of combination (like $(a+b)^2 = a^2 +2ab +b^2$) of each polynomial.



*

*$(a^2-b^2)x^2+2(ad-bc)x+d^2-c^2$

*$2x^2+y^+2x-2xy-2y+1$

*$2x^2-5xy+2y^2-x-y-1$

*$x^6-14x^4+49x^2-36$

*$(a+b)^4+(a-b)^4+(a^2-b^2)^2$

Thank you! very much ....

Looks like most of these can be done through factoring by "grouping".  There are some ways and more practice problems here: http://cnx.org/content/m21901/latest/ 
