(7x² 2y²)²-(2x² 7y²)²
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解题思路:用x2的取值范围、二次函数的的性质、均值不等式,换元法求函数的值域解题过程:
解题思路:根据非负数的行政列出方程求出x,y的值即可求出x²的值解题过程:
8(x平方-2y平方)-x(7x+y)+xy=8x平方-16y平方-7x平方-xy+xy=x平方-4y平方=(x-2y)(x+2y)手机提问的朋友在客户端右上角评价点【满意】即可.再问:太棒了!连我这
-x^y^7+y^8)(这里有问题,x的几次方?再问:就是一次方再答:(x^8-x^7y+x^5y^3-x^4y^4+x^3y^5-xy^7+y^8)(x^2+xy+y^2)=(x^8-x^7y+x^
2(y-x)²-7(x-y)+6(x-y)-3(y-x)²=-(y-x)²-(x-y)=-(x-y)²-(x-y)=-(x-y)[(x-y)+1]=(y-x)(
-8(2x-y)-{7x-[6x+2y-(10x-8y)]}=-16x+8y-[7x-(6x+2y-10x+8y)]=-16x+8y-(7x-6x-2y+10x-8y)=-16x+8y-7x+6x+2
2(2X-7Y)(7Y+2X)+X^2-(-4X+5Y)(-5Y-4X)=2(4X^2-49Y^2)+X^2-(16X^2-25Y^2)=8X^2-98Y^2+X^2-16X^2+25Y^2=-7X^
(x-y)^2+7(x+y)-11(x-y)^2-8(x+y),=-10(x-y)²-(x+y)当x+y=-3,x-y=-1时=-10*(-1)²-(-3)=-10+3=-7
7x+[-3x-3(x-2y)]-[5x-(2x-y)]=7X+[-3X-3X+6Y]-[5X-2X+Y]=7X-3X-3X+6Y-5X+2X-Y=5Y-2X
1/(x-y)-1/(x+y)-2y/(x^2+y^2)-4y^3/(x^4+y^4)-8y^7/(x^8+y^8)=【(x+y)-(x-y)】/(x-y)(x+y)-2y/(x^2+y^2)-4y^
若(x-y)/(x+y)=3那么x-y=3(x+y)x-y=3x+3y故x=-2y所以(x+2y)/(6x-7y)=(-2y+2y)/(6*(-2y)-7y)=0如果不懂,请Hi我,祝学习愉快!
解题思路:由题意x²+y²-4x-2y+8=(x-2)²+(y-1)²+3,然后根据完全平方式的性质进行求解.解题过程:解:∵x2+y2-4x-2y+8=(x2-4x+4)+y2-2y+1+3=(x-
解题思路:本题目应该是9y的平方吧,要不然没法做出来。解题过程:(2x-6y)/(x的平方-9y)=2(x-3y)/[(x-3y)(x+3y)]=2/(x+3y)=2/3
(-3x+7y)(-7y-3x)-(x-3y)(2x+3y)=(3x-7y)(3x+7y)+(3y-x)(3y+2x)后半部分相当于(x+a)(x+b)=x^2+(a+b)x+ab=9x^2-49y^
x(x*x-1)+x(5-x*x)-6y+7=-x+5x-6y+7=2(2x-3y)+7=2*(-4)+7=-8+7=-1再问:能在写详一点吗-x+5x-6y+7再答:x(x*x-1)+x(5-x*x
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)
(x-y)^7÷(y-x)^6+(-x-y)^3÷(x+y)^2=(x-y)^7÷(x-y)^6+[-(x+y)^3]÷(x+y)^2=(x-y)+[-(x+y)]=x-y-x-y=-2y
等于.-3y-10x
展开x^2-2y^2-xy=-5x^2-2y^2+xy=7所以x^2-2y^2=1xy=6上式除以下式,解分式方程x/y=3/2或-4/3(舍去)所以x^2=9y^2=4x=3y=2或x=-3y=-2