2x^2 + 3 x - 1 x + 1 = 5x x - 1 x = 35 nbspnbsp x =
A.\(x = \frac{3}{5}\)  
B.\(x =  - \frac{3}{5}\)   
C.\(x = \frac{5}{3}\)  
D.\(x =  - \frac{5}{3}\)

Tính diện tích hình thang ABCD biết widehat A = widehat
A.\({S_{ABCD}} = \frac{1}{2}\left( {12{x^2} - 3{y^2}} \right)\)
B.\({S_{ABCD}} = \frac{1}{2}\left( {12{x^2} + 6xy - 3{y^2}} \right)\)
C.\({S_{ABCD}} = \frac{1}{2}\left( {12{x^2} - 6xy - 3{y^2}} \right)\)
D.\({S_{ABCD}} = \frac{1}{2}\left( {12{x^2} -12xy+ 3{y^2}} \right)\)

12xy-1 x^3-2x-6 12x^4y - x^2y - x^3 - 3xy - 2x + 6 12x
A.\(\frac{1}{2}{x^4}y - {x^2}y - {x^3} - 3xy - 2x + 6\)
B.\(\frac{1}{2}{x^4}y - {x^2}y - {x^3} - 3xy + 2x + 6\)
C.\(\frac{1}{2}{x^4}y - {x^2}y - {x^3} + 3xy + 2x + 6\)
D.\(\frac{1}{2}{x^4}y - {x^2}y + {x^3} + 3xy + 2x + 6\)

x-yx^2 + xy + y^2 x^3 + y^3 x^3 + 2x^2y + y^3 x^3 - y^3
A.\({x^3} + {y^3}\)
B.\({x^3} + 2{x^2}y + {y^3}\)
C.\({x^3} - {y^3}\)
D.\({x^3} - 2{x^2}y - {y^3}\)

23x^2y3xy-x^2 + y 2x^3y^2 - 23x^4y + 23x^2y^2 2x^3y^2 +
A.\(2{x^3}{y^2} - \frac{2}{3}{x^4}y + \frac{2}{3}{x^2}{y^2}\)
B.\(2{x^3}{y^2} + \frac{2}{3}{x^4}y + \frac{2}{3}{x^2}{y^2}\)
C.\(2{x^3}{y^2} - \frac{2}{3}{x^4}y - \frac{2}{3}{x^2}{y^2}\)
D.\(2{x^3}{y^2} + \frac{2}{3}{x^4}y - \frac{2}{3}{x^2}{y^2}\)

25xyx^2y-5x + 10y 25x^3y^2 + 2x^2y + 4xy^2 25x^3y^2 - 2
A.\(\frac{2}{5}{x^3}{y^2} + 2{x^2}y + 4x{y^2}\)
B.\(\frac{2}{5}{x^3}{y^2} - 2{x^2}y - 4x{y^2}\)
C.\(\frac{2}{5}{x^3}{y^2} - 2{x^2}y + 4x{y^2}\)
D.\(\frac{2}{5}{x^3}{y^2} + 2{x^2}y - 4x{y^2}\)

x-2yx^2y^2 - xy + 2y x^3y^2 - x^2y - 2x^2y^3 + 2xy + 2x
A.\({x^3}{y^2} - {x^2}y - 2{x^2}{y^3} + 2xy + 2x{y^2} - 4{y^2}\)
B.\({x^3}{y^2} + {x^2}y - 2{x^2}{y^3} + 2xy + 2x{y^2} - 4{y^2}\)
C.\({x^3}{y^2} - {x^2}y - 2{x^2}{y^3} + 2xy + 2x{y^2} + 4{y^2}\)
D.\({x^3}{y^2} - {x^2}y - 2{x^2}{y^3} + 2xy - 2x{y^2} - 4{y^2}\)

- 2x^3y2x^2-3y + 5yz - 4x^5y - 6x^3y^2 + 10x^3y^2z -
A.\( - 4{x^5}y - 6{x^3}{y^2} + 10{x^3}{y^2}z\)
B.\( - 4{x^4}y + 6{x^2}y - 10{x^2}yz\)
C.\( - 4{x^5}y + 6{x^3}{y^2} - 10{x^3}{y^2}z\)
D.\( - 4{x^5}y - 6{x^3}{y^2} - 10{x^3}{y^2}z\)

- 2x^3y2x^2-3y + 5yz - 4x^5y - 6x^3y^2 + 10x^3y^2z -
A.\( - 4{x^5}y - 6{x^3}{y^2} + 10{x^3}{y^2}z\)
B.\( - 4{x^4}y + 6{x^2}y - 10{x^2}yz\)
C.\( - 4{x^5}y + 6{x^3}{y^2} - 10{x^3}{y^2}z\)
D.\( - 4{x^5}y - 6{x^3}{y^2} - 10{x^3}{y^2}z\)

x^2 - 2x + 3x - 4 x^3 + 6x^2 - 11x + 12 x^3 + 6x^2 + 11
A.\({x^3} + 6{x^2} - 11x + 12\)
B.\({x^3} + 6{x^2} + 11x + 12\)
C.\({x^3} - 6{x^2} + 11x + 12\)
D.\({x^3} - 6{x^2} + 11x - 12\)