(2x y-6)² (x-1)²最小值-搜答案-拍题作业网

（1）（7-3x)+(5x-6)=7-3x+5x-6=1+2x(2)-(x^2-3)-(7-5x^2)=-x²2+3-7+5x²=4x²-4(3)xy-(3x-2xy)+

公分母：12XY^2.S=n(n-1)每边都按(n-1)个来数,n条边,总共n(n-1)盆.

2,3,4最小公倍数是12x最大是2次,y最大是1次所以是12x²y

6xy²

1.x^4+5x^2-6=(x^2+6)(x^2-1)=(x^2+6)(x-1)(x+1)2.(x+y)(x+y+2xy)+(xy+1)(xy-1)=(x+y)^2+2xy(x+y)+(xy+1)(x

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

3xy[2xy-x(y-2)+x-1]=3xy(2xy-xy+2x+x-1)=3xy(xy+3x-1)=3x^2y^2+9x^2y-3xy

(1)已知x+y=6,xy=-3x^2y+xy^2=xy(x+y)=-3*6=-18(2)x*[2-(1/x)]+(x/x^2-2x)*(x^2-4)=x*(2x-1)/x+[x/x(x-2)]*(x

1.(X+2)(X+3)2.X(Y+1)(Y+1)

X-3Y分之X-Y,同因式为X+2Y.

-3(2x²-xy)+4(x²+xy-6)

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

-3(2x^2-xy)+4(x^2+xy-6)

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

原式=1-3xy+x+(-4x-6xy)=1-3xy+x-4x-6xy=1-3x-9xy

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

用数形结合的方法来做.(x-2)²+(y-2)²=1可以看做是以(2,2)为圆心,1为半径的一个圆.y/x可以看做是这个圆上一点到原点连线的斜率.要求y/x的最值,就是求斜率的最值

1、(-7x^y)(2x^y-3xy^3+xy)=-14x^(2y)+21x^(y+1)y^3-7x^(y+1)y;2、((x-y)^6)/((y-x)^3)/(x-y)=-(x-y)^3/(x-y)

-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

原式=-x²y+2xy²+2x²y²-4xy³-3x³+27x³y-18x²y²+2x²y-18x&

合并同类项,并化简即可

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