3x^2+2y^2-18x+8y+40的最小值同志们,

18(x+y)^8(x-y)^7÷[3(x+y)^3(x-y)^3]^2 【2(x-y)(x-y)(x-y)-8(x-y)(x-y)(x+y)+6y(x-y)(x-y)]/2(x-y)(x-y) 求几个方程组的答案 ｛2x+y=2 {3x-y=7 x=?y=?{x+2y=50 {3x=2y+6 x=?y=?{x+y=40 {10x+8y=370 x、y=?{x+y=5.8 {y=3x+0.6 x=?y=? (x+y)(x+2y)(x+3y)(x+4y)=-40y的值为根号11 23.已知(x+y)3次+8*x的平方*y-16x*y的平方=18,x+2y=3,求x,y的值 (2x+y)²+(x+3y)(x-3y)-x(5x+8y)因式分解 已知x-y=3,求[（x+y)(x-y)-(x-y)^2+2y(x-y)]除以的值 [2(x-y)^5-8(x-y)^2(x+y)+6y(x-y)^2]÷2(x-y)^2[2(x-y)^3-8(x-y)^2(x+y)+6y(x-y)^2]÷2(x-y)^2 【2(x-y)^3-8(x-y)^2(x+y)+6y(x-y)^2】/2(x-y)^2= [(x+2y)(x-2y)-(2x-y)²+(3x-y(2x-5y)]/(-x)的解答 若2/x-1/y=3,求[y/x-y/x-y(x-y/x-x+y)]/x-2y/x的值 x(x-y)2-(y-x)3 分式 (11 18:8:17)已知x/y=2,求x·x-x·y+3y·y/x·x+x·y+6y·y的值 (x+3y)的平方+2(x-y)(x+y)+(x-3y)的平方 2(y-x)的平方-7(x-y)+6(x-y)-3(y-x)的平方 （x-y)^2+7(x+y)-11(x-y)^2-8(X+Y)的计算过程 y=3(x-y),x=2(x-y)求x,y的值 若x-y不等于0,2x-3y=0,则分式(10x-11y)/(x-y)的值是（）?(10x-11y)/(x-y) =[(8x-8y)+(2x-3y)]/(x-y) =8为什么8X-8Y=8？(10x-11y)/(x-y)=[(8x-8y)+(2x-3y)]/(x-y)=8+(2x-3y)]/(x-y)=8+0=8