Tính gtri biểu thức: A = x² + 4xy + 4y² - z² tại x = 5, y = 7 và z = 12

Làm tính nhân: \(\left(x^2y^2-\dfrac{1}{2}xy+2y\right)\left(x-2y\right)\)

Rút gọn biêu thức sau: x^n-1 (x + y) - y(x^n-1 + y^n-1)

Lee and Greg are twins, but they don't dress ................... (identical)

Choose A,B,C or D which is incorrect in each sentence

1. In spite of all our are work hard, a lot of things went wrong.

2. Although we had plan everything carefully, a lot of things went wrong.

3. I went to work the next day although I was still feeling illness.

4. She refused the job although the salary was low.

5. I managed to sleep although the hotel was noise.

6. I couldn't get to sleep in spite of it was quite quiet and dark.

7. He run fast in spite of his old age.

Phân tích đa thức sau thành nhân tử: x² - bx + ax - ab

Phân tích đa thức sau thành nhân tử: xy - z + y - xz