Tìm x

a/ 2x^2 + 8 = 0

b/ ( x - 4 ) . ( 5x - 2 ) - 3. ( x - 4 ) = 0

c/ ( x + 2 ) . ( x^2 - 2x + 4 ) + x . ( 5 - x ) - ( x + 5 ) = -17

d/ ( x^2 + x + 1 ) . ( x^2 + x + 2 ) - 12 = 0

Tìm x 

a/ x² . ( 2x - 3 ) - 12 + 8x = 0

b/ 2010x² - x = 2011

Tính 

a/ ( y^2 - 4 )^2 - ( y - 2 ) . ( 2 + y ) . ( y^2 + 4 )

b/ ( a^2 + a - 4 ) . ( a^2 - a + 4 )

c/ ( 9n^4 - 4n^2 + 4n - 1 ) : ( 3n^2 + 1 - 2n )

tính 

a/ ( 6x^3 - 7x^2 - x + 2 ) : ( 2x + 1 )

b/ ( x^2 - y^2 + 6x + 9 ) : ( x + 3 + y )

Tìm a thuộc R

( 2x^3 - 3x^2 + x + a ) chia hết ( x + 2 )

1 PTĐTTNT

a/ x^2y - 4y + y . ( x - 2 )^2

b/ x^5 - 2x^4 + x^3 - x^3y^2

Tính 

6x^2 - 4x^2 . ( 2x^2 - 5x + 3 )

chứng minh bt này luôn đúng

 $x^2-x+\frac{1}{3}>0$

chứng minh x^2 - x + 1/3 luôn đúng

Tính 

a/( 5x - 2 )^2 - 2 . ( 3x - 1 )^2

b/( 5x + x^3 + 2x^4 - 2 - 3x^2 ) : ( x^2 + 1 - x)