Trắc nghiệm Toán 8: Rút gọn phân thức đại số có lời giải chi tiết (phần 1)

A. $\frac{{\text{y}}^{\text{2}}}{\text{3(x}+\text{3y)}}$

B. $\frac{{\text{3y}}^{\text{2}}}{\text{x}+\text{3y}}$

C. $\frac{{\text{y}}^{\text{2}}}{\text{2(x}+\text{3y)}}$

D. $\frac{\text{xy}}{\text{x}+\text{3y}}$

A. $\frac{\text{6}}{\text{7}}(x-3)$

B. $\frac{6}{7}(3-x)$

C. $\frac{6}{7}{\left(x-3\right)}^2$

D. $\frac{-6}{7}(x-3)$

A. $\frac{\text{a}}{\text{2}+\text{a}}$

B. $\frac{\text{a}-\text{4}}{\text{2}+\text{a}}$

C. -8

D. $\frac{\text{a}-\text{4}}{\text{a}}$

A. $\frac{\text{x}-\text{y}}{\text{5(x}+\text{y)}}$

B. $\frac{\text{5(x}-\text{y)}}{\text{x}+\text{y}}$

C. $\frac{\text{5(x}-{\text{y)}}^{\text{2}}}{\text{x}+\text{y}}$

D. $\frac{\text{5}}{\text{x}+\text{y}}$

A. A = 2

B. A = 3

C. A > 4

D. A = 1

A. T = 27

B. T = 3

C. T = 9

D. T = 18

A. $\frac{{\text{(5a}+\text{5b)}}^{\text{2}}}{{\text{(3a}+\text{3b)}}^{\text{2}}}=\frac{\text{5}}{\text{3}}$

B. $\frac{{\text{(5a}+\text{5b)}}^{\text{2}}}{{\text{(3a}+\text{3b)}}^{\text{2}}}=\frac{\text{25}}{\text{9}}$

C. $\frac{{\text{4x}}^{\text{3}}+{\text{4x}}^{\text{2}}}{{\text{x}}^{\text{2}}-\text{1}}=\frac{{\text{4x}}^{\text{2}}}{{\text{x}}^{\text{2}}+\text{1}}$

D. $\frac{{\text{b}}^{\text{2}}+\text{b}}{\text{a}+\text{ab}}=\frac{\text{a}}{\text{b}}$

A. $\frac{{\text{x}}^{\text{2}}-\text{3xy}}{{\text{21y}}^{\text{2}}-\text{7xy}}=\frac{\text{x}}{\text{7y}}$

B. $\frac{\text{2x}+\text{4}}{{\text{x}}^{\text{2}}-\text{x}-\text{6}}=\frac{\text{4}}{\text{x}-\text{3}}$

C. $\frac{\text{2x}-\text{6y}}{{\text{x}}^{\text{2}}-{\text{9y}}^{\text{2}}}=\frac{\text{2}}{\text{x}+\text{9y}}$

D. $\frac{{\text{x}}^{\text{2}}-\text{2x}}{{\text{x}}^{\text{3}}-\text{4x}}=\frac{\text{1}}{\text{x}+\text{2}}$

A. $\frac{\text{2xy}-{\text{x}}^{\text{2}}}{{\text{2y}}^{\text{2}}-\text{xy}}=\frac{\text{x}}{\text{y}}$

B. $\frac{\text{(x}-\text{2)(x}+\text{4)}}{{\text{x}}^{\text{2}}+\text{7x}+\text{12}}=\frac{\text{x}-\text{2}}{\text{x}+\text{3}}$

C. $\frac{\text{(2x}-\text{4)(x}-\text{3)}}{{\text{(x}}^{\text{3}}-\text{27)(x}-\text{2)}}=\frac{\text{2}}{{\text{x}}^{\text{2}}-\text{3x}+\text{9}}$

D. $\frac{{\text{25xy}}^{\text{2}}}{{\text{40x}}^{\text{3}}{\text{y}}^{\text{2}}}=\frac{\text{5}}{{\text{8x}}^{\text{2}}}$

A. $\frac{{\text{x}}^{\text{3}}-\text{1}}{{\text{x}}^{\text{2}}-\text{2x}+\text{1}}=\frac{{\text{x}}^{\text{2}}+\text{x}+\text{1}}{\text{x}-\text{1}}$

B. $\frac{\text{5(x}-\text{y)}-\text{3(y}-\text{x)}}{\text{10(x}-\text{y)}}=\frac{\text{4}}{\text{5}}$

C. $\frac{{\text{x}}^{\text{2}}+\text{4x}+\text{3}}{\text{2x}+\text{6}}=\frac{\text{x}+\text{1}}{\text{2}}$

D. $\frac{{\text{16x}}^{\text{2}}\text{y(x}+{\text{y)}}^{\text{2}}}{\text{12xy(x}+\text{y)}}=\frac{\text{4(x}+\text{y)}}{\text{3}}$

A. a - b - c

B. a +b + c

C. a - b + c

D. a + b - c

A. x -3

B. $x^2+3$

C. $x^2-3$

D. x + 3

A. x - y

B. $\frac{\text{x}-\text{y}}{\text{x}+\text{y}}$

C. x + y

D. (x - 1)(x + y)

A. -x - y

B. $y^2-x^2$

C. $\frac{-\text{(x}+\text{y)}}{\text{x}-\text{2y}}$

D. x - 2y

A. x = a + 1

B. x = 1 - a

C. x = a + 2

D. x = a - 1

A. $x=\frac{\text{a}+\text{3}}{\text{a}}$

B. $x=\frac{\text{a-3}}{\text{a}}$

C. $x=\frac{\text{a-3}}{\text{a+3}}$

D. $x=\frac{\text{a}}{\text{a+3}}$

A. $\frac{{\text{(a}}^{\text{2}}+{\text{b}}^{\text{2}}\text{)(a}+\text{b)}}{\text{a}-\text{b}}$

B. $\frac{{\text{a}}^{\text{2}}+{\text{b}}^{\text{2}}}{\text{a}-\text{b}}$

C. ${\left(a^2+b^2\right)}^2{\left(a+b\right)}^2$

D. $(a^2+b^2)(a+b)$

A. $\frac{\text{2x}+\text{5}}{\text{3x}+\text{1}}$

B. $\frac{\text{2x}-\text{5}}{\text{3x}-\text{1}}$

C. $\frac{\text{2x-5}}{\text{3x}+\text{1}}$

D. $\frac{\text{2x}+\text{5}}{\text{3x}-\text{1}}$

A. $A=\frac{10}{2}$

B. $A=-\frac{6}{5}$

C. $A=\frac{6}{5}$

D. $A=\frac{25}{2}$

A. $B=\frac{\text{x}}{\text{x}+\text{y}};B=-5$

B. $B=\frac{\text{x+y}}{\text{x}};B=-1$

C. $B=\frac{\text{x}}{\text{x}+\text{y}};B=-1$

D. $B=\frac{\text{-x}}{\text{x}+\text{y}};B=1$

A. $\frac{\text{1}}{\text{5}}$

B. -1

C. 5

D. 6

A. 10

B. 2

C. 5

D. $\frac{\text{1}}{\text{2}}$

A. x = -1

B. x = 0

C. x = 2

D. x = 1

A. $\frac{5}{4}$

B. 1

C. $\frac{4}{5}$

D. 2