x平方家10x加9=0-搜答案-拍题作业网

x²+3x-1=0x²=1-3xx²+3x=1x的立方加5乘以x的平方加5x加18=x³+5x²+5x+18=x(1-3x)+5(1-3x)+5x+1

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平方减3x加1=0,x^2+1=3xx平方除以（x四次方加x平方加1）=x^2/(X^4+X^2+1)=X^2/{(X^2+1)^2-X^2}=X^2/{(3X)^2-X^2}=1/8

x平方加y平方减2xy减6x加6y加9=0x^2+y^2-2xy-6x+6y+9=0(x^2+y^2-2xy)-6(x-y)+9=0(x-y)^2-6(x-y)+9=0(x-y-3)^2=0x-y-3

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

题意是这样的吧：求(x²+9x)/(x²+3x)+(x²-9)/(x²+6x+9)原式=(x²+9x)/(x²+3x)+(x+3)(x-3)

4x平方加y平方减4x减6y加10=0,(4x²-4x+1)+(y²-6y+9)=0(2x-1)²+(y-3)²=0x=1/2,y=3后面的题目看不清.把x=1

x²+3x-10=0;(x+5)(x-2)=0;x=2或x=-5祝你学习进步谢谢

2x^2-6x+3=02x-6+3/x=02x+3/x=6平方(2x+3/x)^2=364x^2+9/x^2+12=364x^2+9/x^2=24

x^2+x-1=0(x+1/2)^2=1-1/4x1=根号3/2-1/2x2=-根号3/2-1/2

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平方+9x=1x平方+9x+81/4=1+81/4(x+9/2)平方=85/4x+9/2=±根号85/2x=-(9-根号85)/2,x=-(9+根号85)/2

zenmuhuo：∵4x²-4x+y²+6y+10=04x²-4x+1+y²+6y+9=0(2x-1)²+(y+3)²=0且(2x-1)&s

4x平方加y平方-4x+6y+10=(2x-1)^2+(y+3)^2=02x-1=0y+3=0x=1/2y=-3x^2+y^2=1/4+9=37/4

2/(x+3)(x-3）+(x-2)/x(x-3)=1/x(x+3)两边乘x(x+3)(x-3)2x+x^2+x-6=x-3x^2+2x-3=0(x+3)(x-1)=0x+3在分母,不等于0所以x=1

这个不用公式发多简单上式等效为（3x+1）=0公式法就是x=[-b±根号（b-4ac）]/2a=-6/2x9=-1/3

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

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