2x 5y-3=0,求x,,y的值
来源:学生作业帮助网 编辑:作业帮 时间:2024/07/14 04:51:20
根据题意得,x+1=0,2x-y+4=0,解得x=-1,y=2,∴x5y+xy5=(-1)5×2+(-1)×25=-2-32=-34.故答案为:-34.
x²+xy+1/4y²+3/4y²-3y+3=0(x+1/2y)²+3/4(y-2)²=0∴x+1/2y=0y-2=0∴x=-1y=2∴y^x=2^(
3x*+xy-2y*=0(3x-2y)(x+y)=0那么x=2y/3或x=-yy/x=3/2或x/y=-1(x/y)-(y/x)-(x*+y*)/(xy)=(x/y)-(y/x)-(x/y+y/x)=
2x-3y=0(1)3x-y-1=0(2)由(2)得y=3x-1(3)把y=3x-1代入(1)得2x-9x+3=0∴x=3/7把x=3/7代入(3)得y=2/7∴x=3/7y=2/7
75=(2x+3y)(3x+2y) =6x^2+13xy+6y^2 =6(x+y)^2+xy>=24xy+xy=25xyxy<=3x+y>=2vxy=2v3最小值2v3再问:6(x+y)^2+xy
:|x+二分之一|+(y-3)的平方=0∴x+1/2=0y-3=0∴x=-1/2y=3(3x+2y)的平方-2(x-y)(x+y)+3(x+y)(x-2y)=9x²+12xy+4y²
/>(x+y+3)(x-y-2)=0x,y互为相反数则x+y=0...(1)带入上式3(x-y-2)=0x-y=2...(2)联立(1)(2)得x=1,y=-1
4x-2y=0→y=2x,把所有的y都用2x替代.结果是-1/7
x=3y再答:带入再答:3.5
三分之二x(3m+1)y3=2/3x^(3m+1)y^3-四分之一x5y(2n+1)=-1/4x^5y^(2n+1)由于二者是同类项,则有3m+1=5,m=4/32n+1=3,n=1,5m+3n=5*
你直接把Y=2X带进式子里面去啊.
x^2+3xy-4y^2/y^2=0x/y=-4or1x-y/x+y=5/3or0
2x+y/x^2-2xy+y^2)*(x-y)=2x+y/(x-y)^2*(x-y)=2x+y/x-yx-3y=0.x=3y将x=3y带入2x+y/x-y=6y+y/3y-y=7/2(二分之七)
x=3y代入(2x+y)/(x^2-2xy+y^2)*(x-y)=7y/(9y^2-6y^2+y^2)*(2y)=7/2
x-3y=0x=3y原式=(2x+y)(x-y)/(x²-2xy+y²)=(2×3y+y)(3y-y)/[(3y)²-2×3y×y+y²]=7y×2y/(9y&
x-3y=0x=3y2x+5y/3x-2y=11y/7y=11/7
错在第(4)步.∵x>y,∴y-x<0.不等式两边同时除以负数y-x,不等号应改变方向才能成立.
先由两已知方程解得x=27/8,y=9/8,然后接下来的自己算啦...两方程的话,先将第二个两边都乘三,再于第一个相减得出y,再将y带进方程得x
再问:能把第三题重新发一遍吗?再答:这三个题本质上式连在一起的再答:这道题应该是希望杯的试题
绝对值项恒非负,两绝对值项之和=0,两绝对值项分别=03x-y=0(1)x+y=0(2)(1)+(2)4x=0x=0,代入(2)y=-x=0(x-y)/(xy)无意义,因此题目错了.