Ответы и объяснения

2013-05-16T13:47:02+04:00
2013-05-16T15:15:27+04:00

(3x+y)(2x-5y)-6(x-y)^2=6x^2-13xy-5y^2-6x^2+12xy-6y^2=-13xy-5y^2+12xy-6y^2=-xy-5y^2-6y^2=-xy-11y^2