2/3xy²×2y²+2/3xy²×3x²= 4/3xy²+2xy²x²= 4/3xy la a 4+2xy³y²,,,,,,,
x³y+1/4x la a 5+4/3y²+1/3x²y,,,,,,,,,,,,,
a) 1/9x²y×3(3x-y²)= 1/3x²y×(3x-y²)=x³y-1/3x²y³,,,,,,,,,,,
c) 5x³+0,5x²y-10xy²-1y³=5x³+0,5x²y-10xy²-y³....................
