`x^2-9=(x-3)(x+3)`
$ x^{2} - 9 = ( x + 3 ) ( x - 3 ) $
Áp dụng hằng đẳng thức số 3
Choose the best answer.
I think you should buy _____ pack of mineral water instead. And you can also buy _____ snacks such as potato crisps, 3 kilos of mandarins, 2 kilos of apples, 3 bunches of bananas, ______ cookies and soft candies.
We should decorate our living room with _____ orange banner. We also need ________ ribbons, balloons, party hats and costume.
I think that ______ cauliflower is not enough for 3 people. Let’s buy one more.