分别以XY为半径画同心圆(X>Y),所得圆环的面积为14π,求式子[-6(x+y)²(x-y)³]²÷[3(x求式子[-6(x+y)²(x-y)³]²÷[3(x +y)(x-y)²]²

问题描述:

分别以XY为半径画同心圆(X>Y),所得圆环的面积为14π,求式子[-6(x+y)²(x-y)³]²÷[3(x
求式子[-6(x+y)²(x-y)³]²÷[3(x +y)(x-y)²]²

圆环面积=πx^2-πy^2=π(x+y)(x-y)=14π
所以(x+y)(x-y)=14
原式=[-6(x+y)^2*(x-y)^3]^2/[3(x+y)(x-y)^2]^2
=36(x+y)^4*(x-y)^6/[9(x+y)^2*(x-y)^4]
=4(x+y)^2*(x-y)^2
=4[(x+y)(x-y)]^2
=196*4
=784

-6(xcvgr)

πx²-πy²=14π
x²-y²=14
分子[-6(x+y)²(x-y)³]²=[-6(x²-y²)²(x-y)]²=[-1176(x-y)]²
分母[3(x +y)(x-y)²]²=[3(x²-y²)(x-y)]²=[42将(x-y)约掉,可得出答案为784

题目是这样吗?[-6(x+y)²(x-y)³]²÷3x

πx²-πy²=14πx²-y²=14分子[-6(x+y)²(x-y)³]²=[-6(x²-y²)²(x-y)]²=[-1176(x-y)]²分母[3(x +y)(x-y)²]²=[3(x²-y²)(...