1. If I lend you$100, when you (repay) ... me?

2. Unless I have a quiet room I (not be able) ... to do any work.

3. If we leave the car here, it (not be) ... in anybody's way.

4. Someone (steal) ... your car if you leave it unlocked

5. If you come late, they (not let) ... you in

6. What (happen) ... if my parachute does not open.

\(\left\{{}\begin{matrix}\dfrac{1}{x-1}+\dfrac{1}{y}=-1\\\dfrac{3}{x-1}-\dfrac{2}{y}=7\end{matrix}\right.\)

\(\left\{{}\begin{matrix}\dfrac{15}{x}-\dfrac{7}{y}=1\\\dfrac{4}{x}+\dfrac{9}{y}=35\end{matrix}\right.\)

tính `(25x^2 +10xy +4y^2) (5x-2y)^2` với x=y+5

`25x^2 +10x+1-49`

`(a+b)xy+ab^2`

`5xy-40a^3 b^3 xy`

phân tích thành phân tử