x²-4xy-6x 3y y²-10因式分解

题目写错应该是求（6xy+7y)+[8x-(5xy-y+6x)]（6xy+7y)+[8x-(5xy-y+6x)]=6xy+7y+8x-5xy+y-6x=xy+2x+8y=xy+2(x+4y)=5+2×

13x^2-6xy+y^2-4x+1=09x²-6xy+y²+4x²-4x+1=0(3x-y)²+(2x-1)²=0∵(3x-y)²≥0&n

1.2(Xy+Xy)-3(Xy-xy)-4Xy=2*2xy-0-4xy=4xy-4xy=02.1/2ab-5aC-(3acb)+(3aC-4aC)=1/2ab-5ac-3acb-ac=1/2ab-6a

个人觉得,不如直接计算6x-2y=-12-1=-132xy^2=2*(-2)*1/4=-1所以（6x-2y)*3/2xy^2=(-13)^3/(-1)=2197xy=-1(xy-3)(xy+1)=0(

解题思路：本题主要利用完全平方公式进行因式分解即可求出结果解题过程：解:x²－6xy＋9y²=(x-3y)2

18(4x²-xy)-19(4x²-xy)+(4x²-xy-1)=72x²-18xy-76x²+19xy+4x²-xy-1=-4x²

5xy+4x+7y+6x-3xy-4xy+3y=5xy-3xy-4xy+4x+6x+7y+3y=（5-3-4）xy+（4+6）x+（7+3）y=-2xy+10x+10y=-2xy+10（x+y）因为x

6x+6y=9x+4y3x-2y=0……1式6x+6y=xy……2式2式-1式乘以2得10y=xyx=10y=15请及时采纳

(1)把括号全打开得xy+2x+8y=xy+2(x+4y)=5-2=3(2)时针速度：30度/时分针速度:360度/时成直角时,分针与时针相差90度,7：00时相差210度,（210-90）÷（360

-3(2x²-xy)+4(x²+xy-6)=6x²+3xy+4x²+4xy-24=-2x²+7xy-24

13x^2-6xy+y^2-4x+1=0(9x^2-6xy+y^2)+4x^2-4x+1=0(3x-y)^2+(2x-1)^2=0加数均非负,和为0.则均为0所以有：3x=y2x-1=0x=1/2y=

唉,肯定是老师布置的作业了,还拿来问百度啊?!自己想.

-3(2x^2-xy)+4(x^2+xy-6)=-6x^2+3xy+4x^2+4xy-24=-2x^2+7xy-24再问：thankyou~

xy+1/xy+y/x+x/y=[(xy)^2+1+x^2+y^2]/(xy)=[(xy)^2-2xy+1+x^2-2xy+y^2+4xy]/(xy)=[(xy-1)^2+(x-y)^2+4xy]/(

[3xy(1-x)-6xy(x-1/2)]*2x*(-xy)平方=(3xy-3x²y-6x²y+3xy)(2x³y²)=12x^4y³-18x^5y&

xy+1/xy>=2√（xy*1/xy）=2(当xy=1/xy即xy=1时取等号)x/y+y/x>=2√（x/y*y/x）=2(当x/y=y/x即x=y取等号)当x=y=1时可以同时满足两项的等号要求

13x^2-6xy+y^2-4x+1=09x^2-6xy+y^2+4x^2-4x+1=0(3x-y)^2+(2x-1)^2=03x-y=0,2x-1=0,x=0.5y=3*0.5=1.5(xy-x^2

-3(2x-xy)-4(-6+xy+x)=-6x+3xy+24-4xy-4x=-10x-xy+24=-10+1+24=15先化简.后代入求值

13x²-6xy+y²-4x+1=0即(9x^2-6xy+y^2)+(4x^2-4x+1)=0∴(3x-y)^2+(2x-1)^2=0x,y在实数范围内(3x-y)^2(2x-1)

-3(2X²-XY)+4(X²+XY-6)=-6X²+3XY+4X²+4XY-24=-2X²+7XY-245(X-2Y)²-X+2Y-60=