1.3x+2y=442x+3y=46x=?y=?( )2.(13.5-81/4-4.75)÷【11/2(A+13/4÷
1.3x+2y=442x+3y=46x=?y=?( )2.(13.5-81/4-4.75)÷【11/2(A+13/4÷
数学题……555{(3x+y)(3x-y)-(x-5y)(5x-y)-(x-2y)²÷(-4x),x=-2.y
3(x+y)-4(x-y)=11,2(x-y)+5(x+y)=27
2x-y=2,求[(x²+y²)-(x-y)²+2y(x-y)]÷4y
[x(x-y)-y(x-y)+(x+y)(x-y)]÷2x其中x=2012 y=2013
{3(x+y)-4(x-y)=4 {x+y/2 + x-y/6=1
x+y/2+x-y/3=6,4(x+y)-3(x-y)=-20
{(x+y)/2+(x-y)/3=6 4(x+y)-3(x-y)=-20
4(x+y)-3(x-y)=-20,2/x+y+3/x-y=6
(x+y)(x+2y)(x+3y)(x+4y)=-40
已知x-2y=2011,求[(3x+2y)(3x-2y)-(x+2y)(5x-2y)]÷4x的值.
化简求值:[(x+y)(x-y)-(x-y)²+2y(x-y)]÷4y,其中x=二分之一,y=2