1+1+2=4

Tìm GTNN chớ bạnbạn

Giả sử \(\sqrt{4+\sqrt{7}}-\sqrt{4-\sqrt{7}}\)\(\le\sqrt{3}\)

<=> 4 + \(\sqrt{7}\)+ 4 - \(\sqrt{7}\)- 2×\(\sqrt{16-7}\)\(\le3\)

<=> 8 - 6 \(\le3\)

<=> 2 \(\le3\)(đúng)

Vậy \(\sqrt{4+\sqrt{7}}-\sqrt{4-\sqrt{7}}\)< √3

khó thế

= ( x + y ) + ( x- y )

tìm lỗi sai

1 .Frank has done his homework and then listened to music

2. Jim learned a lt since he started the language course

3. Helen has finished her lunch and she went out to play

4. They haven't seen each other since Septemper when they have met at Mary's party

5+5=10

A=X²-4X-3

  =X²-X-3X-3

   =(X²-X)-(3X-3)

   =X.(X-1)-3(X-1)

   =(X-3).(X-1)