Mai is at the canteen. She wants some noodles and some coca-cola

Can I help you ?

Yes pleased, I need a bowl of noodles and a glass of coca-cola

Here you are

Thanks. How much are they ?

B=x³+y³=x³+3x²y+3xy²+y³-3x²y-3xy²

=(x+y)²-3xy.(x+y)

thay xy=2 và x+y=-3 ta được:

B=(-3)³-3.2.(-3)

=-27+18

=-9

Vậy B=-9 tại xy=2 và x+y=-3