初一数学,计算题跟化简题要详细过程,谢谢,急要
2、化简(x²/y-x)-(y²/y-x)的结果是()
A、-x-y B、y-x C、x-y D、x+y
3、计算
(1)(x/x-2)-(2/x-2) (2)(x+5y/x+y)+(x-3y/x+y) (3)[x²-y/(x-3)²]-[9-y/(3-x)²] (4)(a²-1/a²-2a)+(4a-5/2a-a²) (5)(9m²/-3m-n)+(n²/n+3m)
4、化简:[a²-b²/(a-b)(a-c)]+[c²-b²/(a-b)(c-a)]
5、化简:(x²+x/x²-1)-(x+1/x-1)
注明:这里的/都表示分数线,每题至少2部。谢谢 展开
1、(1)2/-m+3/m=(1/m) (2)(4/m+3)+(m-1/m+3)=1
2、化简(x²/y-x)-(y²/y-x)的结果是(A)A、-x-y B、y-x C、x-y D、x+y
3、计算
(1)(x/x-2)-(2/x-2)=(x-2)/(x-2)
=1
(2)(x+5y/x+y)+(x-3y/x+y)
=(x+5y+x-3y)/(x+y)
=(2x+2y)/(x+y)
=2
(3)[x²-y/(x-3)²]-[9-y/(3-x)²]
=(x²-y-9+y)/(x-3)²
=(x²-9)/(x-3)²
=(x+3)(x-3)/(x-3)²
=(x+3)/(x-3)
(4)(a²-1/a²-2a)+(4a-5/2a-a²)
=(a²-1-4a+5)/(a²-2a)
=(a-2)²/a(a-2)
=(a-2)/a
(5)(9m²/-3m-n)+(n²/n+3m)
=(n²-9m²)/(n+3m)
=(n+3m)(n-3m)/(n+3m)
=n-3m
4、化简:[a²-b²/(a-b)(a-c)]+[c²-b²/(a-b)(c-a)]
=(a²-b²-c²+b²)/(a-b)(a-c)
=(a+c)(a-c)/(a-b)(a-c)
=(a+c)/(a-b)
5、化简:(x²+x/x²-1)-(x+1/x-1)
=x(x+1)/x(x-1) - (x+1/x-1)
= (x+1/x-1)- (x+1/x-1)
=0
如果你满意,请采纳,谢谢!