1、若x^2+y^2=5,xy=3,求(x+y)^2 （x-y）^2 2、x^+y^=5,x+y=6,求xy 3、若x+

来源：学生作业帮编辑：百度作业网作业帮分类：数学作业时间：2024/07/31 20:32:50

1、若x^2+y^2=5,xy=3,求(x+y)^2 （x-y）^2 2、x^+y^=5,x+y=6,求xy 3、若x+y=6,xy=3,求x^2+y^2 (x-y)^2
1、若x^2+y^2=5,xy=3,求(x+y)^2 （x-y）^2
2、x^+y^=5,x+y=6,求xy
3、若x+y=6,xy=3,求x^2+y^2 (x-y)^2
4、a+b=5,a-b=3,求ab

1.
(x+y)²=x²+y²+2xy=5+2×3=11
(x-y)²=x²+y²-2xy=5-2×3=-1 (题目有问题)
2.
xy=(1/2)[(x+y)²-(x²+y²)]=(1/2)(6²-5)=31/2
3.
x²+y²=(x+y)²-2xy=6²-2×3=30
(x-y)²=(x+y)²-4xy=6²-4×3=24
4.
ab=(1/4)[(a+b)²-(a-b)²]=(1/4)(5²-3²)=4

若x+y-5xy=0,求(2x-3xy+2y)/(x+2xy+y)的值若1/x-1/y=3,求5x+2xy-5y/x-4xy-y的值若(x*x+y*y)(x*x+y*y)-4x*x*y*y=0,求代数式(x*x+5xy+y*y)/(x*x+2xy+y* 若x-y=4,xy=1,求(-2xy+2x+3y)-(3xy+2y-2x)-(x+4y+xy)的值 √x(√x+2√y)=√y(6√x+5√y,求x-3√xy+2y/x+√xy-6y ∫x(∫x+2∫y)=∫y(6∫x+5∫y),求：（x+∫xy-y)/(2x+∫xy+3y) 已知x+y=-1,xy=-2,求代数式-5（x+y)+(x-y)+x(xy+y)的值已知xy=-2,x-y=3,求（x+y)（x-y)-y^2+（x-y)^2-（6x^2y-2xy^2)÷2y 已知（x+2）^2+|x+y+5|=0,求3x^2y-[2x^2y-(2xy-x^2y)-4x^2]-xy 若2x平方+3xy-2y平方=0,求x+y/x-y 若(y-x)/xy=3,求分式(2x+3xy-2y)/(x-2xy-y)的值若y-x/xy=3,求分式2x+3xy-2y/x-2xy-y