Nguyễn Quỳnh Hoa's Profile

6. Cho a,b\geq0.a^{}2^{}+b2=4.Tìm GTLN của M=\frac{ab}{a+b+2}

7.Cho x,y>0.x2+y2=1. Tìm GTNN của A=\frac{-2xy}{1+xy}

8. Cho a,b,c>0. Cm:(3a+b)(2c+a+b)\leqslant(2a+b+c)2

1. It is imperative that the letter (send) ............. at once.

2. By the time tomorrow, we (travel) ............. to Nha Trang.

3. Up to now, we (complete) .............. four tests.

4. The students (punish) ............ yesterday is my brother.

5. I think the play (perform) .............. now.

6. It has been suggested that the government (assist) ................. the poor in improving their living condition.

7. By the time he became a heavy weight boxing champion, he (win) ..................... over thirty fights.

8. He looked frightened as if he (see) .............a ghost.

9.I (sit) ....................... down for a rest while the shoes (repair) ....................

10. During the trip, try to avoid (bite) .......................by moaquitoes.

Cho pt:x² -mx+m-1=0. Gọi x1;x₂ là 2 nghiệm của pt, tìm m để 

2x₁x₂+3/x_1²+x_2²+2(x₁x₂+1)=1

cho phương trình x²-2(m-2)x-4m-16=0

a, CMR:pt sau luôn có nghiệm với mọi giá trị của m

b,Tìm m để pt có 2 nghiệm đối nhau