Bài tập Phép trừ các phân thức đại số (có lời giải chi tiết)

A. $\frac{1}{2}$ 

B. $-\frac{1}{2}$ 

C. $\frac{1}{2x}$ 

D. $\frac{x}{2}$ 

A. $-\frac{1}{x}$ 

B. $\frac{1}{x^2}$

C. $\frac{1}{x}$

D. $-\frac{1}{x^2}$

A. 1

B. 2

C. 3

D. -3

A. $\frac{1-5x}{x(5x+1) }$ 

B. $\frac{1+5x}{x(5x+1) }$ 

C. $\frac{1-5x}{x(5x-1) }$ 

D. $\frac{-1-5x}{x(5x+1) }$ 

A. $\frac{2x+14 }{ (x-2)(x+2)}$ 

B. $\frac{-2x+14 }{ (x-2)(x+2)}$ 

C. $\frac{2x-14 }{ (x-2)(x+2)}$ 

D. $\frac{-2x-14 }{ (x-2)(x+2)}$ 

A. $\frac{12x^2+10x-9}{(x+3)(x-3)}$ 

B. $\frac{12x^2+109x-9}{(x+3)(x-3)}$ 

C. $\frac{12x^2+109x-10}{(x+9)(x-9)}$ 

D. $\frac{12x^2-109x+10}{(x+9)(x-9)}$ 

A. $\frac{2x+5y}{3(2x+y{)}^2}$ 

B. $\frac{2x-5y}{3(2x+y{)}^2}$ 

C. $\frac{2x-5y}{6(2x+y{)}^2}$ 

D. $\frac{2x+5y}{6(2x+y{)}^2}$ 

A. $\frac{x^2-3}{x+1}$ 

B. $\frac{x+3}{x+1}$ 

C. $\frac{x^2-3}{x-1}$

D. $\frac{x^2+3}{x+1}$ 

A. $\frac{-x^3+2x^2+2x-1}{x(x+1)}$ 

B. $\frac{-x^3-2x^2+x-1}{x(x+1)}$  

C. $\frac{x^3-2x^2+x-1}{x(x+1)}$

D. $\frac{-x^3+x^2+x-1}{x(x+1)}$ 

A. $\frac{\text{11x}+\text{13}}{\text{3x}-\text{3}}+\frac{\text{15x}+\text{17}}{\text{4}-\text{4x}}=\frac{-\text{1}}{\text{12}}$

B. $\frac{\text{11x}+\text{13}}{\text{3x}-\text{3}}+\frac{\text{15x}+\text{17}}{\text{4}-\text{4x}}=\frac{-\text{x}-\text{1}}{\text{12(x}-\text{1)}}$

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

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

A. $\frac{\text{2a}}{\text{a}-\text{1}}$

B. $\frac{{\text{2a}}^{\text{2}}+\text{2a}}{\text{(a}-\text{1)(a}+\text{1)}}$

C. $\frac{\text{2a}}{\text{a}+\text{1}}$

D. $-\frac{{\text{2a}}^{\text{2}}}{\text{(a}-\text{1)(a}+\text{1)}}$

A. $\frac{-\text{2}}{\text{x}-\text{3}}$

B. $\frac{\text{2x}}{\text{(x}-\text{3)(x}+\text{3)}}$

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

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

A. Q = -1

B. Q = 0

C. Q = 2

D. Q = 1

A. $\frac{\text{x}}{\text{1}-{\text{x}}^{\text{2}}}+\frac{\text{y}}{\text{1}-{\text{y}}^{\text{2}}}+\frac{\text{z}}{\text{1}-{\text{z}}^{\text{2}}}=\frac{\text{xyz}}{\text{(1}-{\text{x}}^{\text{2}}\text{)(1}-{\text{y}}^{\text{2}}\text{)(1}-{\text{z}}^{\text{2}}\text{)}}$

B. $\frac{\text{x}}{\text{1}-{\text{x}}^{\text{2}}}+\frac{\text{y}}{\text{1}-{\text{y}}^{\text{2}}}+\frac{\text{z}}{\text{1}-{\text{z}}^{\text{2}}}=\frac{\text{3xyz}}{\text{(1}-{\text{x}}^{\text{2}}\text{)(1}-{\text{y}}^{\text{2}}\text{)(1}-{\text{z}}^{\text{2}}\text{)}}$

C. $\frac{\text{x}}{\text{1}-{\text{x}}^{\text{2}}}+\frac{\text{y}}{\text{1}-{\text{y}}^{\text{2}}}+\frac{\text{z}}{\text{1}-{\text{z}}^{\text{2}}}=\frac{\text{4xyz}}{\text{(1}-{\text{x}}^{\text{2}}\text{)(1}-{\text{y}}^{\text{2}}\text{)(1}-{\text{z}}^{\text{2}}\text{)}}$

D. $\frac{\text{x}}{\text{1}-{\text{x}}^{\text{2}}}+\frac{\text{y}}{\text{1}-{\text{y}}^{\text{2}}}+\frac{\text{z}}{\text{1}-{\text{z}}^{\text{2}}}=\frac{\text{xyz(x}+\text{y}+\text{z)}}{\text{(1}-{\text{x}}^{\text{2}}\text{)(1}-{\text{y}}^{\text{2}}\text{)(1}-{\text{z}}^{\text{2}}\text{)}}$

A. 3

B. 0

 C. 2

D. 1