CHO X > 0 THOẢ VÌ

7 - - DE THI TOAN VAO 10 CO DAP AN 7 - - DE THI TOAN VAO 10 CO DAP AN
Lớp 10 DE THI TOAN VAO 10 CO DAP AN

7 -2=7

x x

2

 

x+ 1 9

⇒   ÷  =

x

x+ 1 3 ( 0)

⇒ = >

do x

Nên :

  

1 1 1 1 1 1

+ =   + ÷  − + − + ÷ 

5 4 3 2

x x x x x x

5 2 3 4

   

1 1

=   + −   + ÷  +  

4 2

3 1

3 1 2 7 1

=      + ÷  − − +   

[ ]

= −

3 49 8

=

123

3 3 1 1 (1)

+

3 10

x = + −