已知x²-x-2xy+y+y²,求代数式½(x²+y²)-xy的值
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:2024/04/29 13:45:45
已知x²-x-2xy+y+y²,求代数式½(x²+y²)-xy的值
x²-x-2xy+y+y²=2,求代数式½(x²+y²)-xy的值
x²-x-2xy+y+y²=2,求代数式½(x²+y²)-xy的值
已知x²-x-2xy+y+y²=0
x²-2xy+y²-x+y=0
(x-y)²-(x-y)=0
(x-y)(x-y-1)=0
x-y=0 (x-y-1)=0
(1)x-y=0
代数式½(x²+y²)-xy的值
=1/2(x²+y²-2xy)
=1/2(x-y)²
=1/2* 0²
=0
(2)x-y-1=0
x-y=1
代数式½(x²+y²)-xy的值
=1/2(x²+y²-2xy)
=1/2(x-y)²
=1/2* 1²
=1/2
再问: 发漏了不好意思啊是x²-x-2xy+y+y²=2
再答: x²-x-2xy+y+y²=2 x²-2xy+y²-x+y-2=0 (x-y)²-(x-y)-2=0 (x-y-2)(x-y+1)=0 x-y=2 x-y=-1 (1)x-y=2 代数式½(x²+y²)-xy的值 =1/2(x²+y²-2xy) =1/2(x-y)² =1/2* 2² =2 (2)x-y=-1 代数式½(x²+y²)-xy的值 =1/2(x²+y²-2xy) =1/2(x-y)² =1/2* (-1)² =1/2
x²-2xy+y²-x+y=0
(x-y)²-(x-y)=0
(x-y)(x-y-1)=0
x-y=0 (x-y-1)=0
(1)x-y=0
代数式½(x²+y²)-xy的值
=1/2(x²+y²-2xy)
=1/2(x-y)²
=1/2* 0²
=0
(2)x-y-1=0
x-y=1
代数式½(x²+y²)-xy的值
=1/2(x²+y²-2xy)
=1/2(x-y)²
=1/2* 1²
=1/2
再问: 发漏了不好意思啊是x²-x-2xy+y+y²=2
再答: x²-x-2xy+y+y²=2 x²-2xy+y²-x+y-2=0 (x-y)²-(x-y)-2=0 (x-y-2)(x-y+1)=0 x-y=2 x-y=-1 (1)x-y=2 代数式½(x²+y²)-xy的值 =1/2(x²+y²-2xy) =1/2(x-y)² =1/2* 2² =2 (2)x-y=-1 代数式½(x²+y²)-xy的值 =1/2(x²+y²-2xy) =1/2(x-y)² =1/2* (-1)² =1/2
已知x²-x-2xy+y+y²,求代数式½(x²+y²)-xy的值
已知x+y=4.x-y=6.求代数式xy(y²+y)-y²(xy+2x)-3xy的值
已知实数x,y,xy=5,x+y=7,求代数式x²y+xy²的值
已知2x+y=4.xy=3,求代数式2x²y+xy²的值
已知x²+xy=3,y²+xy=-2,求下列代数式的值.
已知xy=1,求代数式负三分之一x(xy²+y+x³y四次方)的值
已知y分之x=½,求代数式x²-xy-2y²分之x²+2xy+y²的值
已知x²-xy=4,y²-xy=9求下面代数式的值(1)x²-2xy+y²;(2
已知x,y满足x²+y²+5/4=2x+y,求代数式xy/(x+y)的值.
已知x+y=3,xy=-6,求代数式x²+y²的值
已知x+y=5,求代数式x²+xy+5y的值
已知x-y=3,求代数式(x+y)(x-y)+(x-y)²-(2xy-2y)²的值