若x+y=7,xy=12,则x^2-xy+y^2为和值

来源：学生作业帮助网编辑：六六作业网时间：2024/08/14 09:52:20

若x+y=7,xy=12,则x^2-xy+y^2为和值若x+y=7,xy=12,则x^2-xy+y^2为和值若x+y=7,xy=12,则x^2-xy+y^2为和值x^2-xy+y^2＝x^2+2xy+

若x+y=7,xy=12,则x^2-xy+y^2为和值
若x+y=7,xy=12,则x^2-xy+y^2为和值

若x+y=7,xy=12,则x^2-xy+y^2为和值
x^2-xy+y^2
＝x^2+2xy+y^2-3xy
＝（x+y）^2-3xy
=7^2-3x12
=49-36
=13

x^2-xy+y^2
=（x+y)^2-3xy
=7*7-3*12
=49-36
=13

x^2-xy+y^2=x^2+y^2+2xy-3xy=(x+y)^_3xy=7^2-3*12=49-36=13

已知x-xy=20,xy-y=12,则x-y= ,-2xy+x+y= 已知x-xy=20 xy-y=12,则x-y=（）,x+y-2xy=（）. 已知:x-xy=20,xy-y=12,则x-y=...,-2xy+x+y=... 若x+y分之xy=2,则-x+3xy-y分之3x-xy+3y=多少? 若xy/x+y=2,则3x-5xy+3y/-x+3xy-y=?/是分之若x+y分之xy=2,则-x+3xy-y分之3x-xy+3y=多少? 若xy/x+y=2,则3x-xy+3y/-x+3xy-y= 已知xy/x+y=3,则代数式2x-7xy+2y/-x+xy-y的值是多少? 若x-y=4,xy=1,则(2x+y-2xy)-(3x+2y+xy)-(4xy+3y-5x)= 若x+y=7,xy=12,则x^2-xy+y^2为和值 |x|/x+y/|y|+xy/|xy|= 已知x+y=1,xy=-2,则x²y+xy²-2xy x*x+xy=3,xy+y*y=2,则x*x+2xy+y*y=________? |x-2|+|y-2|=0,求xy=?；|x|=-|y-7|,则xy=? x^2-7xy+12y^2=0,求x^2-2xy+y^2/2xy的值如果x+y=0,xy=-7,则x^2y+xy^2=? 如果X+Y=10 XY=7则X~2Y+XY~2=? 若 x+y=5,xy=-50 则x^2y+xy^2 =( )