x次数2加10x加21=0-搜答案-智慧作业帮

应该是x^2-2x+y^2+6y+10=0配方：x^2-2x+1+y^2+6y+9=0(x-1)^2+(y+3)^2=0得x=1y=-3所以x+y=-2

x^2-2x+y^2+6y+10=0(x-1)^2+(y+3)^2=0(x-1)^2=0x-1=0x=1(y+3)^2=0y+3=0y=-3x+y=1-3=-2

原式=（x+2y)^2-（x+2y）+1/4=0则x+2y=1/2

x^2-2x+y^2+6y+10=0x^2-2x+1+y^2+6y+9=0(x-1)^2+(y+3)^2=0x-1=0,y+3=0x=1,y=-3(x-y)/(x+y)=4/(-2)=-2

x^2+y^2-4x-10y+29=0x^2-4x+4+y^2-10y+25=0(x-2)^2+(y-5)^2=0x=2y=5x^y+xy^2=xy(x+y)=2*5(2+5)=70

x^2+y^2-2x+6y+10=0(x-1)^2+(x+9)^2=0欲等式成立x=1,y=-9于是x+y=-8

(x+1)(x+2)(x+3)(x+4)+1=[(x+1)(x+4)][(x+2)(x+3)]+1=(x^2+5x+4)(x^2+5x+6)+1把x^2+5x看做A,所以原式化成：(A+4)(A+6)

负三分之一x减x的平方y加2π,有3项每项的系数和次数分别是负三分之一、1；-1、3；2π、0.

x^2+10x+21=0(x+3)(x+7)=0x+3=0x+7=0解得x1=-3,x2=-7

问题求什么?再问：求x加y的值再答：x^2-2x+1+y^2-6y+9=0(x-1)^2+(y-3)^2=0x=1y=32x+3y=11

x²-2x+y²+6y+10=0(x²-2x+1)+(y²+6y+9)=0(x-1)²+(y+3)²=0∴x-1=0,y+3=0∴x=1,y

(x-1)(x+2)(x+3)(x+6)+20=0(x-1)(x+6)(x+2)(x+3)+20=0(x^2+5x-6)(x^2+5x+6)+20=0(x^2+5x)^2-36+20=0(x^2+5x

4

-x^2+2x+3=0x^2-2x-3=0(x-3)(x+1)=0x=3或x=-1

x的平方加y的平方加2x-6y+10=0即：(x+1)^2+(y-3)^2=0所以：x=-1,y=3.所以：x+y=2.

似乎是x1=-1,x2=-9

原式=x³-2x²-x²+x+2=x²(x-2)-(x²-x-2)=x²(x-2)-(x-2)(x+1)=(x-2)(x²-x-1

(x+1)(x+2)+1/4=x²+3x+2+1/4=x²+3x+9/4=x²+2*3x/2+(3/2)²=(x+3/2)²

由题意可得x²+y²+2x+6y+10=0（x+1）²+（y+3）²=0所以x=-1,y=-3

由题意,知m=1,n=2所以原多项式可化为-4*x的平方+3x+7所以当x=-2时原式=-15