若x^2-y^2=40 x+y=8/5 则x-y=——

若x^2-y^2=40,(x+y)=8/5,则x-y= x-y/x-x+y/y-(x+y)(x-y)/y² y/x=2 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 已知x-y/x+y=3,求代数式5(x-y)/x+y-x+y/2(x-y) 若【x+y=5,2x+y=8】,则x+2y= (4x-2y-z)-{5x[8y-2y-(x+y)]-x+(3y-10z)]=? kuaihuajian 【2(x-y)^3-8(x-y)^2(x+y)+6y(x-y)^2】/2(x-y)^2= 若实数x、y满足x平方+y平方-4x-2y+5=0,求根号8y-2x分之（根号x）+y 若实数X,Y满足x²+y²-4x-2y+5=0求√x+y/√8y-2x 3x-2y=9 x-3y=2 x+y=5 x+2y=3 y=x 2x+y=8 若3x-5y=0,则x+y/x=（）,x-y/y=（）,2x-3y/2x+3y=( ) x+y=1 5x-2y=8 3x-y=7 2x-y=3x表示y和用y表示x 若x-y=1 化简（x+y)(x^2+y^2)(x^4+y^4)(x^8+y^8)(x^16+y^16) 若x-y/x+y=5,求x-y/2x+2y+5x+5y/3x-3y的值 若x^2-y^2=40 x+y=8/5 则x-y=—— 若x+y分之x-y=3,求式子x+y分之5(x-y)—2(x-y)分之x+y的值 若x-y分之x+y=3,求式子x+y分之5(x-y)—2（x-y）分之x+y的值 若2/x-1/y=3,求[y/x-y/x-y(x-y/x-x+y)]/x-2y/x的值