2X的2次方Y-8Y-搜答案-神马作文网

观察可知分子为(-x)^(2n+1)=-x^(2n+1)分母为y^(2n)所以第六个式子-x^13/y^12第n个式子是-x^(2n+1)/y^(2n)

(x-y)的2次方-2(x-y)+(x-y)-5(x-y)=(x-y)²-2(x-y)+(x-y)-5(x-y)=(x-y)²-(x-y)-5(x-y)=(x-y)²-6

[2(x一y)³一8(x一y)²(x+y)+6y(x一y)²]÷2(x一y)²=(x一y)一4(x+y)+3y=x-y-4x-4y+3y=-3x-2y再答：不客

(x-y)(z+y-x+y+2y)÷4y=(x-y)(z-x+4y)÷4y{(x+y)(x-y)-(x-y)的2次方+2y(x-y)}除以4y=(x-y)(x+y-x+y+2y)÷4y=(x-y)(4

解题思路：本题目主要考查指数的运算，其中的关键是通过提取负号把y-x转化成-（x-y)解题过程：

【(4x的3次方-1/2y)的2次方+4y(x的2次方-y/16)】除以8x的2次方=(16x的6次方-4x³y+y²/4+4x²y-y²/4)÷（8x

-3x的2次方y+4x的2次方y+5x的2次方y-7x的2次方y+1-绝对值8x的2次方y的2次方=(-3+4+5-7)x^2y+1-8x^2y^2=-x^2y-8x^2y^2+1

10

2的x次方=8的y+1次方2的x次方=2的3（y+1）次方x=3（y+1）=3y+3----------------（1）81的y次方=9的x-5次方3的4y次方=3的2（x-5）次方4y=2（x-5

8^Y+1=2^3^Y+19^y=3^2^y依题意得3y+3=x2y+9=3y+3解得X=21Y=6

再答：不客气。

解原式=(x^2+y^2)-(xy)^2=(x^2+xy+y^2)(x^2-xy+y^2)

原式=-16x²y³+20x²y²=-4x²y²(4y-5)

(x+3y)(x-3y)(x²-9y²）=(x²-9y²)(x²-9y²)=(x²-9y²)²=x^4-18x

-8x^2y^2+2x^3y+8xy^3=2x^3y-8x^2y^2+8xy^3=2xy(x^2-4xy+4y^2)=2xy(x-2y)^2

等量代换,解得等于3

由x的2次方-y的2次方=8得（X+Y）(X-Y)=8X-Y=2所以X+Y=4两式相加X=3Y=1

(x+y)的平方+2*4(x+y)+4的平方(x+y)=(x+y+4)的平方

【(x-y)的3次方-8(x-y)的2次方(x+y)+6y(x-y)的平方】/2(x-y)的平方=(x-y)²[x-y-8(x+y)+6y]/2(x-y)²=1/2（x-y-8x-

(x—y)的2次方×（x—y)的5次方×（y-x)=-(x-y)的2次方×（x-y)的5次方×（x-y)=-(x-y)的(2+5+1)次方=-(x-y)的8次方