Rewrite these following sentences with the same meaning

1. "You shouldn't write too many shorthands" The programmer said -> The programmer..................

2. "Decorate the house before Tet" My father said -> My father...............

3. "My mother wrote a letter to her friend last night" He said -> He said..............

4. "His teacher let him write shorthand" -> His teacher allowed.............

5. "Kate gave me a book yesterday" He said -> He said...........

6. " Where is my umbrella?" she asked -> She asked...............

7. "How are you?" Martin asked us -> Martin asked us.................

8. He asked, "Do I have to do it?" -> He asked.............

9. "Where have you been?" the mother asked her daughter -> The mother asked her daughter...............

10. "Which dress do you like best?" she asked her boyfriend -> She asked her boyfriend................

Giải các hệ PT sau:

a) \(\left\{{}\begin{matrix}2x^2-3xy=y^2-3x-1\\2y^2-3xy=x^2-3y-1\end{matrix}\right.\)

b) \(\left\{{}\begin{matrix}x^3-2y=4\\y^3-2x=4\end{matrix}\right.\)

c) \(\left\{{}\begin{matrix}\sqrt{x+1}-\sqrt{7-y}=4\\\sqrt{y+1}-\sqrt{7-x}=4\end{matrix}\right.\)

d) \(\left\{{}\begin{matrix}2x^2=y+\frac{1}{y}\\2y^2=x+\frac{1}{x}\end{matrix}\right.\)

Cho a,b,c là các số thực. CMR: \(a^2+\frac{b^2}{4}\) ≥ ab

Giải phương trình:

a) \(\sqrt{4x^2+20x+25}+\sqrt{x^2-8x+16}=\sqrt{x^2+18x+81}\)

b) \(2x^2-8x-3\sqrt{x^2-4x-5}=12\)

Tìm x để biểu thức có nghĩa:

a) \(\frac{1}{\sqrt{x-\sqrt{2x-1}}}\)

b) \(\frac{\sqrt{16-x^2}}{\sqrt{2x+1}}+\sqrt{x^2-8x+8}\)

Giải các PT sau:(đặt ẩn phụ)

a) x² - 4x + 2 = 2\(\sqrt{x^2-4x+5}\)

b) \(\sqrt{\left(4+x\right)\left(6-x\right)}\) = x² - 2x - 12

Cho tam giác ADC vuông tại A có đường cao AH. Biết góc D= 65 độ , AH=3cm.

a) Tính độ dài AD.

b) Trên nửa mặt phẳng bờ DC chứa điểm A, vẽ tia Cx song song với AD. Trên Cx lấy điểm B sao cho CB = DA. Tính: khoảng cách từ B đến AD; độ dài đoạn BD và diện tích tam giác ABD