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1. 下列代数式中,是分式的是 (
A.$2026x$
B.$\dfrac{1}{x+1}$
C.$\dfrac{x+1}{2}$
D.$π x^2$
B
)A.$2026x$
B.$\dfrac{1}{x+1}$
C.$\dfrac{x+1}{2}$
D.$π x^2$
答案
1.B
2. 若分式$\dfrac{x-2}{x+3}$的值为0，则实数$x$的值为 （
A.2
B.0
C.1
D.$-3$
A
）A.2
B.0
C.1
D.$-3$
答案
2.A
3. 下列分式变形正确的是 （
A.$\dfrac{a}{-a + b} = -\dfrac{a}{a + b}$
B.$\dfrac{2a + b}{a^2} = \dfrac{2 + b}{a}$
C.$\dfrac{ab}{ab - b^2} = \dfrac{a}{a - b}$
D.$\dfrac{a^2 + b^2}{a + b} = a + b$
C
）A.$\dfrac{a}{-a + b} = -\dfrac{a}{a + b}$
B.$\dfrac{2a + b}{a^2} = \dfrac{2 + b}{a}$
C.$\dfrac{ab}{ab - b^2} = \dfrac{a}{a - b}$
D.$\dfrac{a^2 + b^2}{a + b} = a + b$
答案
3.C
4. 下列分式是最简分式的是 （
A.$\dfrac{x}{xy}$
B.$\dfrac{x}{3x+1}$
C.$\dfrac{6}{3y}$
D.$\dfrac{x+1}{x^2 - 1}$
B
）A.$\dfrac{x}{xy}$
B.$\dfrac{x}{3x+1}$
C.$\dfrac{6}{3y}$
D.$\dfrac{x+1}{x^2 - 1}$
答案
4.B
5. 分式$\frac{1}{x^2 - y^2}, \frac{1}{x^2 + xy}$的最简公分母是 （
A.$x^2 - y^2$
B.$x^2 + xy$
C.$(x^2 - y^2)(x^2 + xy)$
D.$x(x + y)(x - y)$
D
）A.$x^2 - y^2$
B.$x^2 + xy$
C.$(x^2 - y^2)(x^2 + xy)$
D.$x(x + y)(x - y)$
答案
5.D
6. 把$\frac{1}{x-2},\frac{1}{(x-2)(x+3)},\frac{2}{(x+3)^2}$通分,下列相关过程错误的是 （
A.最简公分母是$(x-2)(x+3)^2$
B.$\frac{1}{x-2}=\frac{(x+3)^2}{(x-2)(x+3)^2}$
C.$\frac{1}{(x-2)(x+3)}=\frac{x+3}{(x-2)(x+3)^2}$
D.$\frac{2}{(x+3)^2}=\frac{2x-2}{(x-2)(x+3)^2}$
D
）A.最简公分母是$(x-2)(x+3)^2$
B.$\frac{1}{x-2}=\frac{(x+3)^2}{(x-2)(x+3)^2}$
C.$\frac{1}{(x-2)(x+3)}=\frac{x+3}{(x-2)(x+3)^2}$
D.$\frac{2}{(x+3)^2}=\frac{2x-2}{(x-2)(x+3)^2}$
答案
6.D
7. 把$\frac{4}{3a^2b},\frac{a-b}{ab^2c}$通分,下列计算正确的是 （
A.$\frac{4}{3a^2b}=\frac{4b}{3a^2b^2},\frac{a-b}{ab^2c}=\frac{a^2-ab}{3a^2b^2c}$
B.$\frac{4}{3a^2b}=\frac{4bc}{3a^2b^2c},\frac{a-b}{ab^2c}=\frac{3a^2-3ab}{3a^2b^2c}$
C.$\frac{4}{3a^2b}=\frac{4b}{3a^2b^2c},\frac{a-b}{ab^2c}=\frac{3a^2-3ab}{3a^2b^2c}$
D.$\frac{4}{3a^2b}=\frac{4bc}{3a^2b^2c},\frac{a-b}{ab^2c}=\frac{3a^2-ab}{3a^2b^2c}$
B
）A.$\frac{4}{3a^2b}=\frac{4b}{3a^2b^2},\frac{a-b}{ab^2c}=\frac{a^2-ab}{3a^2b^2c}$
B.$\frac{4}{3a^2b}=\frac{4bc}{3a^2b^2c},\frac{a-b}{ab^2c}=\frac{3a^2-3ab}{3a^2b^2c}$
C.$\frac{4}{3a^2b}=\frac{4b}{3a^2b^2c},\frac{a-b}{ab^2c}=\frac{3a^2-3ab}{3a^2b^2c}$
D.$\frac{4}{3a^2b}=\frac{4bc}{3a^2b^2c},\frac{a-b}{ab^2c}=\frac{3a^2-ab}{3a^2b^2c}$
答案
7.B
8. 以下分式化简:① $\frac{4x+2}{6x-1}=\frac{2x+2}{3x-1}$;② $\frac{x+a}{x+b}=\frac{a}{b}$;③ $\frac{x^2+y^2}{x+y}=x+y$;④ $\frac{x^2-y^2}{x+y}=x+y$。其中错误的有 （
A.1个
B.2个
C.3个
D.4个
D
）A.1个
B.2个
C.3个
D.4个
答案
8.D
