Cho các sơ đồ phản ứng xảy ra theo đúng tỉ lệ molE + 2
A.4
B.5
C.3
D.2

Hỗn hợp X gồm Cu CuO Fe Fe2O3 Hòa tan hết m gam X tron
A.1,30%.
B.2,60%.
C.3,25%.
D.3,90%.

x^3 - 5x^2 + 6x - 4x^2 + 10x - 4 x x - 3 2 2x - 1 -
A.\(\frac{{x\left( {x - 3} \right)}}{{2\left( {2x - 1} \right)}}\)
B.\(\frac{{ - x\left( {x - 3} \right)}}{{2\left( {2x - 1} \right)}}\)
C.\(\frac{{ - x\left( {x + 3} \right)}}{{2\left( {2x - 1} \right)}}\)
D.\(\frac{{x\left( {x + 3} \right)}}{{2\left( {2x - 1} \right)}}\)

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

x^3 - 5x^2 + 6x - 4x^2 + 10x - 4 x x - 3 2 2x - 1 -
A.\(\frac{{x\left( {x - 3} \right)}}{{2\left( {2x - 1} \right)}}\)
B.\(\frac{{ - x\left( {x - 3} \right)}}{{2\left( {2x - 1} \right)}}\)
C.\(\frac{{ - x\left( {x + 3} \right)}}{{2\left( {2x - 1} \right)}}\)
D.\(\frac{{x\left( {x + 3} \right)}}{{2\left( {2x - 1} \right)}}\)

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

Phân thức 5x - 73x^2 + 6x xác định khi x ne 0 x ne  - 2
A.\(x \ne 0\)
B.\(x \ne  - 2\)
C.\(x \ne 0\);\(x \ne  - 2\)
D.\(x \ne 3\);\(x \ne 0\);\(x \ne  - 2\)

x^3 - 5x^2 + 6x - 4x^2 + 10x - 4 x x - 3 2 2x - 1 -
A.\(\frac{{x\left( {x - 3} \right)}}{{2\left( {2x - 1} \right)}}\)
B.\(\frac{{ - x\left( {x - 3} \right)}}{{2\left( {2x - 1} \right)}}\)
C.\(\frac{{ - x\left( {x + 3} \right)}}{{2\left( {2x - 1} \right)}}\)
D.\(\frac{{x\left( {x + 3} \right)}}{{2\left( {2x - 1} \right)}}\)

Biểu thức P = x - 12 - xx - 1x + 2x - 24 - x^2 có kết q
A.\(\frac{1}{{2 - x}}\)
B.\(\frac{{x + 2}}{{x - 2}}\)
C.\(\frac{{x + 2}}{{2 - x}}\)
D.\(\frac{1}{{x - 2}}\)

Tìm biểu thức Q biết 5xx^2 + 2x + 1Q = xx^2 - 1 x + 1x
A.\(\frac{{x + 1}}{{x - 1}}\)
B.\(\frac{{x - 1}}{{x + 1}}\)
C.\(\frac{{x - 1}}{{5\left( {x + 1} \right)}}\)
D.\(\frac{{x + 1}}{{5\left( {x - 1} \right)}}\)