1.x^4-2x^2y-3y^2+8y-42.观察下列各式并在括号内填入适当的数：3^2-1=1*（ ）5^2-1=3*（ ）7^2-1=6*（ ）通过以上各式的观察填空,你能猜测到怎样的规律并说明这个规律是否正确.如果正确,请予以证明.

因式分解：a(x-y)^2+b(y-x)^3 4(x-y)^2+8(y-x)(x+y)1.a(x-y)^2+b(y-x)^3 2.4(x-y)^2+8(y-x)(x+y) 1.（（y+2x)(-2x+y)+4(x+2y)^2)/3y 2.（2(x-y)^3-8(x-y）^2(x+y)+6y(x-y)^2）/2（x-y)^2 4x-3y/x-2y÷6y-8x/y-2x 81/8*(-x-y)^6*(x-y)^3*4/9(x+y)^4*(y-x)^2 【2(x-y)(x-y)(x-y)-8(x-y)(x-y)(x+y)+6y(x-y)(x-y)]/2(x-y)(x-y) 计算(x^8-x^7y+x^5y^3-x^4y^4+x^3y^5-x^y^7+y^8)(x^2+xy+y^2) (x-y) (x-2y)+(x+2y) (x-3y)-2(x-3y) (x-4y)= 计算:1/(x-y)-1/(x+y)-2y/(x^2+y^2)-4y^3/(x^4+y^4)-8x^7/(x^8+y^8) (x+3y-4)(2x-y) 计算（2x-3y)(x+4y)-(3x+y)(x-2y)（2x-3y)(x+4y)-(3x+y)(x-2y) 因式分解(x-2y)(x-3y)+(x-4y)(x-5y)+（x-3y)(x-5y)+(x-2y)(x-4y) [2(x-y)^5-8(x-y)^2(x+y)+6y(x-y)^2]÷2(x-y)^2[2(x-y)^3-8(x-y)^2(x+y)+6y(x-y)^2]÷2(x-y)^2 x^3+2x^2y-4x-8y 【2(x-y)^3-8(x-y)^2(x+y)+6y(x-y)^2】/2(x-y)^2= (2x+y)(2x-3y)+x(2y+y) 2a(x-y)-4b(x-y) (4x-2y-z)-{5x[8y-2y-(x+y)]-x+(3y-10z)]=? kuaihuajian (2x+y)²+(x+3y)(x-3y)-x(5x+8y)因式分解 [(x+y)(x-y)-(x-y)²+2y(x-y)]÷4y