y=(3x^5-4x^3)(4x^5+3x^3)求导

（5x+3y)(3y-5x)-(4x-y)(4y+x)= 4(x-y)-3(x-y)=9 5(x-y)+2(x-y)=11 3(x+y)-4(x-y)=11,2(x-y)+5(x+y)=27 3(x+y)+2(x-y)=36 4(x+y)-5(x-y)=2 先化简再求值(x-y)(x-2y)+(x-2y)(x-3y)-2(x-3y)(x-4y) x=4 y=5 若2x-3y+4=0则x（x*x-1)+x(5-x*x)-6y+7 因式分解(x-2y)(x-3y)+(x-4y)(x-5y)+（x-3y)(x-5y)+(x-2y)(x-4y) 3X=5Y （X+Y)*3X=(2Y+X)*4+2*2 分解因式 x(x-y)^5+xy(y-x)^4-x^3(x-y)3 用递归法求y=x-(x*x*x/3!)+(x*x*x*x*x/5!)-(x*x*x*x*x*x*x/7!)+. 化简[(3x+4y)^2-(2x+y)(2x-y)+(-x+y)(5x-y)]除以-2y,其中x=-1,y=1 （x+y-5)*（x+y-5)+（x-y+3)=0 x*x-y*y 已知:3x-5y=0,求x/y,x-y/y,x-y/x xy²/(x²y-y) × x²/(x²+x)=(x²-3x)/(x²-5x) × 2x-10/(x²-6x+9)=化简求植x²-1/(x²-x-2)除以x/2x-4,其中x=1/2[x-x/(x+1)]除以[x/(2x-4)] ,其中x=√2+1 高数求极限 y=[(3^x +4^x +5^x)/3]^(1/x) (x->0) （5x-3y)(3y+5x)-(4y-3x)(3x-4y) 5/4(x+y)(-x-y)^3*[-4/3(x-y)]*[-3/5(y-x)^2] 5x^3y(x-y)^3-10x^4y^3(y-x)^2因式分解