X-2Y=3,X 5-Y 2=1
来源:学生作业帮助网 编辑:作业帮 时间:2024/07/05 14:52:33
![X-2Y=3,X 5-Y 2=1](/uploads/image/f/890048-56-8.jpg?t=X-2Y%3D3%2CX+5-Y+2%3D1)
x=log2(y)则X1+2X2+3X3=log2(y1)+2log2(y2)+3log2(y3)=log2(y1)+log2(y2^2)+log2(y3^3)=log2(y1y2^2y3^3)=1所
∵x²-2xy-3y²=0∴*(x-3y)(x+y)=0∴x=3y或x=-y(1)2x+y/x-2y当x=3y时,原式=7y/y=7当x=-y时,原式=y/(-3y)=-1/3(2
(x-1)^2+(y-1)^2=1令x-1=sinay-1=cosa则x=1+sina,y=1+cosax^2+y^2=1+2sina+(sina)^2+1+2cosa+(cosa)^2=3+2(si
原式=[2(2x+y)]2-3x2-y2+2-2y2=4(2x+y)2-3(x2+y2)+2∵2x+y=7,x2+y2=5∴原式=183.
你这个题目可能没有写全,根据你提供的条件,Y在X5时=1,如果X在(1,5)之间,Y无解这样就可以做了,在窗体上画一个Command控件,编写如下代码PrivateSubCommand1_Click(
sn=(2-3x5^-1)+(4-3x5^-2)+…+(2n-3x5^-n)=(2+4+.+2n)-(3x5^-1+3x5^-2+.+3x5^-n)=(2^1+2^2+.+2^n)-(3x5^-1+3
已知2x=3y,求xy/(x^2+y^2)-y^2/(x^2-y^2)的值2x=3y-->x=(3/2)yx^2=(9/4)y^2xy/(x^2+y^2)-y^2/(x^2-y^2)==(3/2)y*
y^2=x^3-3x^2+2xx^2=y^3-3y^2+2y两式相减得:y^2-x^2=(x^3-y^3)-3(x^2-y^2)+2(x-y)(x-y)(x^2+xy+y^2-2x-2y+2)=0所以
原式=-x2-y2-3xy-x2+y2=-2x2-3xy,当x=-1,y=2时,原式=-2×(-1)2-3×(-1)×2=4.
[(x^2+y^2)-(x-y)^2+2y(x-y)]÷4y=1(x^2+y^2-x^2+2xy-y^2+2xy-2y^2)÷4y=1(4xy-2y^2)4y=12x-y=24x/(4x^2-y^2)
x2+y2=(x+y)2-2xy=14x3+y3=(x2+y2)×(x+y)-xy2-yx2=14×4-xy(x+y)=52……剩下的就是这么个算法,手机党,求个最佳哈
x+y=1(x+y)^2=x^2+2xy+y^2=1(x+y)^3=x^3+y^3+3xy(x+y)=1而x^3+y^3=1/3,代入得:3xy=2/3xy=2/9由于x=1-y;故代入xy=2/9;
可设x²+y²=t.则t(t-1)=2.===>t²-t-2=0.===>(t-2)(t+1)=0.===>t=2.即x²+y²=2.
由题意得,5+3x≠0,解得x≠-53.故答案为:x≠-53.
x²-2xy+y²/x²-y²=(x-y)²/(x-y)(x+y)=(x-y)/(x+y)因为x=3,y=-5,所以(3-(-5))/(3+(-5))
X^2+y^2=(x+y)^2-2Xy=a^2-2bx3次方+y3次方=(x+y)(X^2+y^2-xy)=a(a^2-2b-b)=a^3-3abx4次方+y4次方=(x^2+y^2)^2-2x^2y
解题思路:运用完全平方公式和平方差公式进行化简,再代入数值进行计算解题过程:解:
因为x²+4y²+x²y²-6xy+1=0(x²-4xy+4y²)+(x²y²-2xy+1)=0(x-2y)²