已知-3X^2y^a+1 +x^3y-3x^4-2是五次四项式,单项式-3x^3by^3-a与多项式-3x^2y^a+1+x^3y-3x^4-2次数相同,求1/1×2+1/2×3+1/3×4+1/4×5+1/5×6+1/6×7+1/7×8+1/8×9-2/b的值

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 已知方程组 2x+y=3a x-2y=a 求x/y 已知x-y/x+y=3,求代数式5(x-y)/x+y-x+y/2(x-y) 已知：2x+y=6,x-3y=1 求7y(x-3y)(x-3y)-2(3y-x)(3y-x) 已知x-y=1,求[(x+2y)^2+(2x+y)(x-4y)-3(x+y)(x-y)]除以y的值大神们帮帮忙 已知x-y=1,求[(x+2y)²+(2x+y)(x-4y)-3(x+y)(x-y)]÷y的值 已知3x+2y=a,2x+3y=b,则(x+y)(x-y)=? 已知x-y=3,求[（x+y)(x-y)-(x-y)^2+2y(x-y)]除以的值 已知3x =2y 求x/x+y+y/x-y-y²/x²-y² 已知6x^2-7xy-3y^2+14x+y+a=(2x-3y+b)(3x+y+1),则a=?,b=? 已知:6x²-7xy-3y²+14x+y+a=(2x-3y+b)(3x+y+1)求a,b的值 已知:6x²-7xy-3y²+14x+y+a=(2x-3y+b)(3x+y+1)求a,b的值 已知集合A={(x,y)|2x-3y=1},B={(x,y)|3x+2y=1}求A交B 已知关于x,y的方程组{2x+3y=2a+5 2x-3y=6a-1的解满足x>0,y 已知集合A={（x,y）|3x+2y=1},B={（x,y）|x-y=2},求A∩B 已知A=｛（x,y）/ y=-x+3｝,B=｛（x,y）/ y=2x-1｝,求A交B 已知A={(X,Y)|Y=2X-1},B={(X,Y)|Y=X+3},求A∩B快 已知集合a(x,y)2x-y-5=0 b(x,y)x+3y+1=0 求A∩B 具体步骤