1.分式m+3/m-2与分式1/m²-4的最简公分母是( ) A、m-2 B、m²-4 C、m+2
3个回答

1.分式m+3/m-2与分式1/m²-4的最简公分母是( B) A、m-2 B、m²-4 C、m+2 D.(m-2)(m²-4)

2.通分:1/x²-x,-1/x²-2x+1 要详细

1/x(x-1)=(x-1)/x(x-1)²

-1/(x-1)²=-x/x(x-1)²

3.若分式2a/a+b的a、b的值同时扩大到原来的10倍,则此分式的值(D )

A是原来的20倍 B是原来的10倍 C是原来的1/10倍 D不变

4.已知(1/a)-(1/b)=(1/2),则ab/a-b的值是( D )

A.1/2 B.-1/2 C.2 D.-2

(b-a)/ab=1/2

ab/(b-a)=2

ab/(a-b)=-2

5.与分式(-x+y)/(-x-y)相等的是(B )

A.(x+y)/(-x-y) B.x-y/x+y C.-(x+y)/(x-y) D.x+y/x-y

(x-y)/(x+y)

6.下列等式中,不成立的是( A )

A.(x²-y²/x-y)=x-y B.(x²-2xy+y²/x-y)=x-y C.(xy/x²-xy)=(y/x-y) D.(y²-x²/xy)=(y/x-x/y)

7.化简:((x-y)²-1)/(x-y-1)=______.

=(x-y-1)(x-y+1)/(x-y-1)=x-y+1

8.不改变分式的值,把下列各式的分子和分母中各项系数都化为整数.

(1)(0.01x+0.5)/(0.3x-0.04); (同乘以100) (2) (1/5x-2y)/(0.3x+y). (同乘以10)

=(x+50)/(30x-4) =(2x-20y)/(3x+10y)