5x+y=26,2x-4y=-16的解

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 解方程组 10（x-y)=3(x+y)+15 6(x+y)=4(2x-y)+1610（x-y)=3(x+y)+156(x+y)=4(2x-y)+16分开的。 求5x-2y=x-y=4x-3y-2的解 x*x+4y*y+2x*x-4y+2=0求根号下5x*x+16y*y的值快啊 5x+y=26,2x-4y=-16的解 关于X,Y的方程组3X+2Y=2m+5与x-y=4m-5的解x,y满足x+2y 若x*x+4*y*y+2*x-4*y+2=0,求5*x*x+16*y*y的算术平方跟 6-4x-x^2=5/|sin(y/x)cos(y/x)|的解 已知X.x+y.y-4x+2y+5=0,求4X.X-12X Y+9Y.y的值 4x-(2x+y+16)/2=-6y 2x+3y=7-x-2y4x-(2x+y+16)/2=-6y 2x+3y=7-x-2y求方程组的解 证明：代数式[(x+y)(x-y)-(x+y)^2-2y(x-y)-2xy]/xy 的值为x,y的值无关 解方程 (x+1)^5/(-1-x)^4=3x+7一定要100%正确阿. 二阶非齐次线性微分方程y''-4y'-5y=(x^2)*(e^2x)的解 已知x*x-4xy+4y*y=0 求[2x(x+y)-y(x+y)]/(4x*x-4xy+y*y)的值? 解方程组(x+y)(x-2y)=-5 (x-y)(x+2y)=7 x*x+2x+y*y-4y+5=0 x= y= 3(x+y)+2(x-y)=36 4(x+y)-5(x-y)=2 4(x-y)-3(x-y)=9 5(x-y)+2(x-y)=11 3(x+y)-4(x-y)=11,2(x-y)+5(x+y)=27