已知x+y=7,xy=9求(x-y)^2的值
来源：学生作业帮助网 编辑：六六作业网 时间：2024/11/23 06:01:26
已知x+y=7,xy=9求(x-y)^2的值已知x+y=7,xy=9求(x-y)^2的值已知x+y=7,xy=9求(x-y)^2的值(x-y)²=x²+y²-2xy=x&
已知x+y=7,xy=9求(x-y)^2的值
已知x+y=7,xy=9求(x-y)^2的值
已知x+y=7,xy=9求(x-y)^2的值
(x-y)²
=x²+y²-2xy
=x²+y²+2xy-4xy
=(x+y)²-4xy
=7²-4*9
=13
(x-y)^2
=(x+y)^2-4xy
=7^2-4x9
=49-36
=13
(x-y)^2=(x+y)^2-4xy=49-36=13
(x-y)^2=(x+y)²-4xy=49-36=13
13
x+y=7 则 (x+y)^2=x^2+y^2+2xy=49 则 x^2+y^2=31
(x-y)^2=x^2+y^2-2xy=13
已知x-xy=8,xy-y=-9,求x+y-2xy的值
已知X+y=6,xy=7 求x^2y+xy^2=已知X+y=6,xy=7 x^2y+xy^2
已知x=3y,试求（x-y)^2+2xy-y^2/x^2+7xy+y^2
已知x=3y,试求(x-y)^2+2xy-y^2/x^2+7xy+y^2
已知x^2-6xy+9y^2=0,求(x-y)/(x+y)
已知x*x+xy-2y*y=7 求整数x y的值
已知,x-y=2,xy=7 求x^2 y-xy^2
已知x+y=0,xy=-7,求x^2y+xy^2
已知xy^2=-2求xy（2x^3y^7+5x^2y
已知x+y=2,xy=7求x²y+xy²的值
已知整数x和y,满足x^+xy-2y^=7,求xy的值
已知x+y=7,xy=9求(x-y)^2的值
已知x*x-4xy+4y*y=0 求[2x(x+y)-y(x+y)]/(4x*x-4xy+y*y)的值?
已知(1/x)-(1/y)=5,求(6x+7xy-6y)/(8y-9xy-8y)
已知：x(x-50y)+xy=50y^2,求：(x-y):y=?
已知X/Y=2/7,求x^2-3XY+2Y^2/X^2-2XY+Y^2
已知X+Y=3,XY=-1,求2(X-Y)^4-9(X-Y)^2+12XY
已知x+y=-5,xy=7,求x^2y+xy^2-x-y的值