1. She liked exercising.
    * Negative statement: She didn't like exercising.
    * Question: Did she like exercising?
2. My family always spends time doing housework together on Sundays.
    * Negative statement: My family doesn't always spend time doing housework together on Sundays.
    * Question: Does your family always spend time doing housework together on Sundays?
3. I used a lot of suncream during my holiday.
    * Negative statement: I didn't use a lot of suncream during my holiday.
    * Question: Did you use a lot of suncream during your holiday?
4. My community organised a fair to raise money for the homeless last week.
    * Negative statement: My community didn't organize a fair to raise money for the homeless last week.
    * Question: Did your community organize a fair to raise money for the homeless last week?
5. Tim makes beautiful pieces of art from dry leaves and sticks.
    * Negative statement: Tim doesn't make beautiful pieces of art from dry leaves and sticks.
    * Question: Does Tim make beautiful pieces of art from dry leaves and sticks?

`A=7x^2+5y^2-6xy=3(x^2-2xy+y^2)+4x^2+5y^2=3(x-y)^2+4x^2+5y^2>=0AAx;y``

Biểu thức đã cho không âm.

Mình nghĩ v

Cho nhận định sau, hãy cho biết nhận định đúng hay sai? Vì sao?

1. Hỗn hợp criolit và nhôm oxit có nhiệt độ nóng chảy cao hơn nhôm oxit.

hức

Điểm khác nhau giữa (1) và (2) là phòng học thứ nhất rất bừa bộn, trong khi phòng học (2) ngăn náp/gọn gàng.

thấy viết thế hay mà, mấy thầy cô hay viết. (viết chữ đfcm ở giấy đẹp hơn gõ này nhiều )

mình quen viết kiểu thế r,