Răspunsuri

2014-11-11T22:06:43+02:00
2x·5x+2x·7y-2x·1-3y·5x-3y·7y+3y·1=...
a·a²+a·ab+a·b²-b·a²-a·ab-b·b²=...
a²-a·ab+a·b²+b·a²-b·ab+b·=...
2014-11-11T22:47:41+02:00