x·x+2x·x+2x²-x·(3x) = ?
3y·(2y²)-y³+4·(2y³)-2y³= ?
3a·(-a)+2a²-(-3a²)+a²·2= ?
b²·b²+b³·b-(-b la 4)+2b·(2b³)

dau coroana