求间算 1/(x-5y)－1/(x-6y)－1/(x-8y)＋1/(x-9y)=

来源：学生作业帮编辑：作业帮分类：数学作业时间：2024/07/18 21:01:16

1/(x-5y)－1/(x-6y)－1/(x-8y)＋1/(x-9y)
=1/(x-5y)－1/(x-8y)＋1/(x-9y)－1/(x-6y)
=[(x-8y)-(x-5y)]/[(x-5y)(x-8y)]+[(x-6y)-(x-9y)]/[(x-9y)(x-6y)]
=(-3y)/[(x-5y)(x-8y)]+ 3y/[(x-9y)(x-6y)]
=3y*{ 1/[(x-9y)(x-6y)] - 1/[(x-5y)(x-8y)] }
=3y*[(x-5y)(x-8y) - (x-9y)x-6y)]/[(x-9y)(x-6y)(x-5y)(x-8y)]
=3y*[(x²-13xy+40y²)-(x²-15xy+54y²)]/[(x-9y)(x-6y)(x-5y)(x-8y)]
=3y*(2xy-14y²)/[(x-9y)(x-6y)(x-5y)(x-8y)]
=6y²(x-7y)/[(x-9y)(x-6y)(x-5y)(x-8y)]

求间算 1/(x-5y)－1/(x-6y)－1/(x-8y)＋1/(x-9y)= ｛4/(x+y)+6/(x-y)=3 ｛9/(x-y)-1/(x+y)=1 1、x(x-y)(x+y)-x(x+y)^2 先化简再求值(x-y)(x+y)-(x-2y) 的完全平方+x(3x-5y)-(x-y)(x-2y),其中x=1/2 y x+y=3 x+2y=9 3/x+1=y y-x=3 y=2x-3 y-3x=1 2(x+1)-y=6 7x-5y=-9 已知4x=9y求(1)x+y/y (2)y-x/2x {3(x+y)-4(x-y)=4 {x+y/2 + x-y/6=1 (1)(x^2/x)-y-x-y 9y=3x-(x-1),4(x+y)-(2x+4)=8y [(-x-y)(-x+y)-(x+y)^2-x(y-y^2)}÷1/2y y＝5；x＝14；y＝（（x＝3*y,x＋6）,x－1）； printf（''x＝%d,y＝%d' 化简[(3x+4y)^2-(2x+y)(2x-y)+(-x+y)(5x-y)]除以-2y,其中x=-1,y=1