已知(x+y)^2=7,(x-y)=3.求x^4+y^4的值;x^6+y^6的值.

来源：学生作业帮助网编辑：六六作业网时间：2025/02/07 04:16:44

已知(x+y)^2=7,(x-y)=3.求x^4+y^4的值;x^6+y^6的值.已知(x+y)^2=7,(x-y)=3.求x^4+y^4的值;x^6+y^6的值.已知(x+y)^2=7,(x-y)=

已知(x+y)^2=7,(x-y)=3.求x^4+y^4的值;x^6+y^6的值.
已知(x+y)^2=7,(x-y)=3.求x^4+y^4的值;x^6+y^6的值.

已知(x+y)^2=7,(x-y)=3.求x^4+y^4的值;x^6+y^6的值.
题目打错了吧应该是（x-y)^2=3吧?
如果这样
则
(x+y)²=7
x²+y²+2xy=7 (1)
(x-y)²=x²+y²-2xy=3 (2)
(1)+(2)
2(x²+y²)=10
x²+y²=5
(1)-(2)
4xy=4
xy=1
x²+y²=5
平方
x^4+y^4+2x²y²=25
x^4+y^4=25-2(xy)²=23
x^6+y^6
=(x²+y²)(x^4-x²y²+y^4)
=5*(23-1²)
=110

已知：2x+y=6,x-3y=1 求7y(x-3y)(x-3y)-2(3y-x)(3y-x) 已知x-y/x+y=3,求代数式5(x-y)/x+y-x+y/2(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 已知方程组{(X+Y)-3(X-Y)=7,2(X+Y)+(X-Y）=-7}则(X+Y)(X-Y)= 已知（x+y）2 =2,(x-y)3 =3,求(x+y)7(x-y)2(x+y)3(y-x)4 的值已知实数x.y满足根号(x+y-8)+根号(8-x-y)=根号(3x-y-4)+根号(x-2y+7),求x,y 已知|x|=2,|y|=3,|x+y|=-(x+y)求x-y 已知f(x+y,y/x)=x^2-y^2,则f(x,y)= 已知x≠y,x^2-x=y^2-y,求x+y的值. 已知x>0,Y>0,如何证x^2/y+y^2/x>=x+y 已知x+2y=3则x=? x-y=7则y=? 已知|x-2y|+|5x-7y-2|则,x = y= 已知(x-y)^2+|5x-7y-2|=0,求x,y的值. 已知2x-y=-3,求代数式5(x-3y)-2(x-7y) 已知x-y=3,求代数式7-x+y-(x-y)^2的值.-.- 已知|5x-y-8|+(7y-x+2)=0则4x+6y 已知x*x+xy-2y*y=7 求整数x y的值