作业帮(x+y)^2=18,(x-y)^2=6,分别求x^2+y^2及x^2+3xy+y^2的值
来源：学生作业帮助网 编辑：作业帮 时间：2024/09/10 14:23:51
x)ӨЮԌ35Ѩ3tv=XlcSEve.˸{>i "}
tPv[RmJIP1]X}ӟr\[9`fFpy0E`5ƶF6yvP9P# Zla6@ t*3M iH1aF09V)M N
(x+y)^2=18,(x-y)^2=6,分别求x^2+y^2及x^2+3xy+y^2的值
(x+y)^2=18,(x-y)^2=6,分别求x^2+y^2及x^2+3xy+y^2的值
(x+y)^2=18,(x-y)^2=6,分别求x^2+y^2及x^2+3xy+y^2的值
(x+y)^2=18=x^2+y^2+2xy,(x-y)^2=x^2+y^2-2xy=6
得出xy=3
x^2+y^2=(x+y)^2-2xy=18-6=12
x^2+3xy+y^2==(x+y)^2+xy=18+3=21
x^2+y^2＝12
x^2+3xy+y^2=21
x^2+y^2=[(x+y)^2+(x-y)^2]/2=(18+6)/2=12
x^2+3xy+y^2=(x+y)^2+xy=(x+y)^2+[(x+y)^2-(x-y)^2]/4=18+(18-6)/4=21
x-y/x-x+y/y-(x+y)(x-y)/y² y/x=2
【2(x-y)^3-8(x-y)^2(x+y)+6y(x-y)^2】/2(x-y)^2=
x+y/2+x-y/6=5 2(x+y)-3(x-y)=-2
（x+y）/2- x-y/2=6 3(x+y)=4(x-y)
x+y/3+x-y/2=6 4(x+y)-2(x-y)=40
[(2x-y)(2x+y)+y(y-6x)]÷2x=?
2(x+y)-3(x-y)=1 6(x+y)+(x-y)=51
{3(x+y)-4(x-y)=4 {x+y/2 + x-y/6=1
{6(x-y)-7(x+y)=21 {2(x-y)-5(x+y)=-1
6(x-y)-2(x+y)=14 3(x-y)+(x+y)=5
x+y/2+x-y/3=6,4(x+y)-3(x-y)=-20
{(x+y)/2+(x-y)/3=6 4(x+y)-3(x-y)=-20
4(x+y)-3(x-y)=-20,2/x+y+3/x-y=6
若(x-y)/(x+y)=3 则(x+2y)/(6x-7y)等于
x,y 满足x(x-2)-y(y-6)=-10,求x,y的值
x+y/2+ x-y/2=6 2(x+y)-3x+3y=24 求X Y
已知X*X+Y*Y+6X-8Y+25=0 求（Y/X)+(X/Y)-2=?
x*x+2x-y*y+6y-8=0,x+y不等于2,求x-y的值