已知圆C:x²-(1 a)x y²-ay a=0-搜答案-大师作文网

∵A=3X²Y-4XY²,B=-X²Y-2XY²A+2B+C=0∴C=-A-2B=-(3x²y-4xy²)+2(x²y+2xy&#

因为A=-x²+2xy-3y²,B=5x²-xy+2y²所以（1）4A-6B=4*(-x²+2xy-3y²)-6(5x²-xy+2

A+B-3C=08x²y-6xy²-3xy+7xy²-2xy+5x²y-3C=0(13x²y-5xy+xy²)/3=CC-A=(13x&su

C=-(A+B)=-(2x^2+3xy-2x+(-)x^2+xy-1)=-x^2-4xy+2x+2x^2表示x的平方

A+B=-2C带入,解放成.一定能消.2、同类项,所以N=2,M=3,之后的式子提取公因式：MN(M+N+1)再问：谢谢你、但我比较笨啦、能不能教我一下第一题哇？可以给你分的。

A=3x^2y-4xy^2B=-x^2y-2xy^2A+B=3x^2y-4xy^2-x^2y-2xy^2=2x^2y-6xy^2A+B+C=0C=-(A+B)=-(2x^2y-6xy^2)=6xy^2

A=2x^2-3xy+2y^2B=2x^2+xy-3y^2C=x^2-xy-2y^2A-(B-(C-(A+B)))=A-(B-(C-A-B))=A-(B-C+A+B)=A-B+C-A-B=C-2B=(

题目里的ab去哪了啊?有没弄错啊?

解C=2A-B=2(2x²-3xy+2y²)-(x²+xy-3y²)=(4x²-x²)+(-6xy-xy)+(4y²+3y

把c用ab表示出来.然后在减a.就是简单的运算.

多项式A、B、C有公因式．∵A=3x²-12=3（x²-4）=3（x+2）（x-2）,B=5x²y³+10xy³=5xy³（x+2）,C=（

=4

解C=(-A-B)/2=-2x^2y+xy-2xy^2C-A=-7x^2y-3xy+xy^2

A=5x^2y-3xy^2+4xyB=7xy^2-2xy+x^2y2C=-A-B2C-2A=-3A-B=-15x^2y+9xy^2-12xy-7xy^2+2xy-x^2y=-16x^2y+2xy^2-

答案见下图

2AB²-C=2(2x²+3xy-y²)(-1/2xy)²-(1/8x³y³-1/4x²y^4)=2(2x²+3xy-y

A+B+C=(x+3xy-5xy+6y-1)+(y+2xy+xy-2x+2)+(x-4xy+3xy-7y+1)=(x-2x+x)+(6y+y-7y)+(3xy+xy-4xy)+(-5xy+2xy+3x

因为|2x+1|+(y-4)^=0所以x=-1/2,y=4其余的该会了吧

根据基本不等式,算术平均≥调和平均所以（x^2/a^2+y^2/b^2）\2≥2\(a^2/x^2+b^2/y^2)所以1\2≥2\(a^2/x^2+b^2/y^2)所以a^2/x^2+b^2/y^2

A=5x^2y-3xy^2+4xyB=7xy^2-2xy+x^2y2C=-A-B2C-2A=-3A-B=-15x^2y+9xy^2-12xy-7xy^2+2xy-x^2y=-16x^2y+2xy^2-