1、(-y^3)^5/y^3/ y^2+2(-y)^102、(x-y)^7/(y-x)^6+(x+y)^3/(x+y)^23、已知X^a=5,x^b=3,求X^(3a-2b)的值

y(y-2)²-y(y+3)(y-5) y=1/2 化简求值 y(y-2)²-y(y+3)(y-5) y=1/2 化简求值 y(y-2)²-y(y+3)(y-5) y=1/2 化简求值 y (3y^2+8y-3)-6y(3y+2y-1)+9y 2(y-4)(3y+2)-5(-3y+7)(y+1),其中y=-1 5y∧2-(y-2)(3y+1)-2(y+1)(y-5) 解方程：3y^2-(2y+1)(y-1)=(y-5)(y+1) 解方程3y^2-(2y+1)(y-2)=(y-5)(y-1) 解方程：3y²-(2y+1)(y-2)=(y-5)(y+1) y-(y-1)/2=1-(2y-3)/5 y-y-1/2=3-y+2/5 解方程y-[3y-1]等于5【y+2] 通分 y+3/y*y-6y+9,1/2y+6,y-1/y*y-9 y-1/y-2 - y-3/y-4=y-2/y-3 - y-4/y-5一共有四个分数哦~希望可以快一点~谢谢! 计算：[(y+1)/(y^2-4y+3)减去(y-2)/(y^2-6y+9)]除以(y-5)/(y-1) 计算：(-3y)^2(2y+1)-(3y-5)(3y+4) 解3y+5/3y-6=1/2+5y-4/2y-4 3（Y+1）^2-5(Y+1)(Y-1)+2(Y-1)^2,化简