4x+5y=28

5x-4y(y-x)=?5x-4y(y-x)=?5x-4y(y-x)=?5x-4y(y-x)=5x-4y^2+4xy=5x-4y²+4xy5x-4y^2+4xy

5x-6y=-28,3x+4y=6求x与y5x-6y=-28,3x+4y=6求x与y5x-6y=-28,3x+4y=6求x与y5x-6y=-28(1)3x+4y=6(2)(1)×2+(2)×310x-

x+y／y=5／4,则x／y=----------------x+y／y=5／4,则x／y=----------------x+y／y=5／4,则x／y=----------------x+y/y=5

已知：4x=5y,求(x+y)：y已知：4x=5y,求(x+y)：y已知：4x=5y,求(x+y)：y4x=5y,x/y=5/4(x+y)/y=x/y+1=5/4+1=9/44x=5yx=5y/4=(

（5x+3y)(3y-5x)-(4x-y)(4y+x)=（5x+3y)(3y-5x)-(4x-y)(4y+x)=（5x+3y)(3y-5x)-(4x-y)(4y+x)=（5x+3y)(3y-5x)-(

x*x+2x+y*y-4y+5=0x=y=x*x+2x+y*y-4y+5=0x=y=x*x+2x+y*y-4y+5=0x=y=x^2+2x+y^2-4y+5=0x^2+2x+1+y^2-4y+4=0(

4(x-y)-3(x-y)=95(x-y)+2(x-y)=114(x-y)-3(x-y)=95(x-y)+2(x-y)=114(x-y)-3(x-y)=95(x-y)+2(x-y)=11打错了吧,这样

3(x+y)-4(x-y)=11,2(x-y)+5(x+y)=273(x+y)-4(x-y)=11,2(x-y)+5(x+y)=273(x+y)-4(x-y)=11,2(x-y)+5(x+y)=27化

3(x+y)+2(x-y)=364(x+y)-5(x-y)=23(x+y)+2(x-y)=364(x+y)-5(x-y)=23(x+y)+2(x-y)=364(x+y)-5(x-y)=23(x+y)+

先化简再求值(x-y)(x-2y)+(x-2y)(x-3y)-2(x-3y)(x-4y)x=4y=5先化简再求值(x-y)(x-2y)+(x-2y)(x-3y)-2(x-3y)(x-4y)x=4y=5

若(x*x+y*y)(x*x+y*y)-4x*x*y*y=0,求代数式(x*x+5xy+y*y)/(x*x+2xy+y*y)的值若(x*x+y*y)(x*x+y*y)-4x*x*y*y=0,求代数式(

y=|-x.x+4x+5|y=|-x.x+4x+5|y=|-x.x+4x+5|答：y=|-x^2+4x+5|的图像如下图,对称轴x=2：

已知x*x+4x+y*y-2y+5=0,则x*x+y*y=?已知x*x+4x+y*y-2y+5=0,则x*x+y*y=?已知x*x+4x+y*y-2y+5=0,则x*x+y*y=?X^2表示平方X^2

化简[(3x+4y)^2-(2x+y)(2x-y)+(-x+y)(5x-y)]除以-2y,其中x=-1,y=1化简[(3x+4y)^2-(2x+y)(2x-y)+(-x+y)(5x-y)]除以-2y,

17.3x+8y=51x+6y=2718.9x+3y=994x+7y=9519.9x+2y=383x+6y=1820.5x+5y=457x+9y=6921.8x+2y=287x+8y17.3x+8y=

请解答方程组：（39）2x+y=5(40)x+y=7(41)2x+3y=12(42)2x+y=3ax+3y=72x-y=83x+4y=173x-5y=11(43)3x+y=82(44)3(x-1)=y

几道数学题急啊对了再加20分(x+y)^2-(x+y)^3(x-y)^2-(x-y)^3(x-y)^2-(y-x)^32(x-y)-3(y-x)^24ab(a+b)^2-6a^2b(a+b)(x+y)

化简求值：2(x+y)(x-2y)-2x(x+y),其中x、y满足x^2+y^2-2x+4y=-5化简求值：2(x+y)(x-2y)-2x(x+y),其中x、y满足x^2+y^2-2x+4y=-5化简

已知5x-4y=0,求x:y和x+y:y的值已知5x-4y=0,求x:y和x+y:y的值已知5x-4y=0,求x:y和x+y:y的值5X-4Y=0,所以5X＝4Y,所以X：Y＝4：5由5X＝4Y得：X

4x=5y(y不等于0).则有.y.y/x.x-y.y=?4x=5y(y不等于0).则有.y.y/x.x-y.y=?4x=5y(y不等于0).则有.y.y/x.x-y.y=?4x=5y所以x=5y/4