若x,y皆是正整數，滿足x^2=y^2(xy^42y^2)的數對(x,y)

x-y/x-x+y/y-(x+y)(x-y)/y²y/x=2x-y/x-x+y/y-(x+y)(x-y)/y²y/x=2x-y/x-x+y/y-(x+y)(x-y)/y²

若2/x-1/y=3,求[y/x-y/x-y(x-y/x-x+y)]/x-2y/x的值若2/x-1/y=3,求[y/x-y/x-y(x-y/x-x+y)]/x-2y/x的值若2/x-1/y=3,求[y

若f(x+y,y/x)=x^2-y^2,则F(X,Y)=若f(x+y,y/x)=x^2-y^2,则F(X,Y)=若f(x+y,y/x)=x^2-y^2,则F(X,Y)=令X=x+y,Y=y/x,解得x

若(x-y)/(x+y)=3则(x+2y)/(6x-7y)等于若(x-y)/(x+y)=3则(x+2y)/(6x-7y)等于若(x-y)/(x+y)=3则(x+2y)/(6x-7y)等于若(x-y)/

若x*x+y*y=x+y-1/2,求x,y的值如题若x*x+y*y=x+y-1/2,求x,y的值如题若x*x+y*y=x+y-1/2,求x,y的值如题

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(

若2x=3y,则(x*x+y*y)/x*x=?若2x=3y,则(x*x+y*y)/x*x=?若2x=3y,则(x*x+y*y)/x*x=?y/x=2/3(x^2+y^2)/(x^2)=1+(y/x)^

填空：x-y/x+y=()/x^2-y^2填空：x-y/x+y=()/x^2-y^2填空：x-y/x+y=()/x^2-y^2分子分母同时乘以x-y即(x-y)^2/(x+y)(x-y)=(x-y)^

（x-y)2•(y-x)³(x-y)=?（x-y)2•(y-x)³(x-y)=?（x-y)2•(y-x)³(x-y)=?答：（x-y)

若集合A={(x,y)|y>=|x-2|},B={(x,y)|y若集合A={(x,y)|y>=|x-2|},B={(x,y)|y若集合A={(x,y)|y>=|x-2|},B={(x,y)|yA∩B在

y"+y''-2y=2xy"+y''-2y=2xy"+y''-2y=2xy"+y''-2y=2x先求y"+y''-2y=0的通r²+r-2=0,r=1或-2y=ce^x+de^(-2x)再求一个特解,

微分方程y"-2y''+y=x微分方程y"-2y''+y=x微分方程y"-2y''+y=x先求对应齐次方程的特征方程为r″-2r+1=0r1=r2=1齐次方程的通解为Y=e^x(C1+C2x)再求非其次方程

(x-y)(x-2y)+(x+2y)(x-3y)-2(x-3y)(x-4y)=(x-y)(x-2y)+(x+2y)(x-3y)-2(x-3y)(x-4y)=(x-y)(x-2y)+(x+2y)(x-3

(x+y)(x-y)+(x-y)平方-(x-y)(3x-y)其中x=-2y=3分之一(x+y)(x-y)+(x-y)平方-(x-y)(3x-y)其中x=-2y=3分之一(x+y)(x-y)+(x-y)

已知x-y/x+y=3,求代数式5(x-y)/x+y-x+y/2(x-y)已知x-y/x+y=3,求代数式5(x-y)/x+y-x+y/2(x-y)已知x-y/x+y=3,求代数式5(x-y)/x+y

化简y(x+y)+(x+y)(x-y)-x^2化简y(x+y)+(x+y)(x-y)-x^2化简y(x+y)+(x+y)(x-y)-x^2y(x+y)+(x+y)(x-y)-x^2=(x+y)(y+x

化简(x^2-y^2)/(x+y)解法一：(x^2-y^2)/(x+y)=(x+y)(x-y)/(x+y)=x-y解法二：(x^2-y^2)/(x+y)=(x^2-y^2)(x-y)/(x+y)(x-

(x-4y)(2x+y)=(x-4y)(2x+y)=(x-4y)(2x+y)=：(x-4y)(2x+y)=2x^2+xy-8xy-4y^2=2x^2-7xy-4y^22x^2-8xy+xy-4y^2=

(x+y)(2x-3y)=?(x+y)(2x-3y)=?(x+y)(2x-3y)=?（x+y）（2x-3y）=2x-3xy+2xy-3y=2x-xy-3y

x+y>=2,x-yx+y>=2,x-yx+y>=2,x-y由题意的x≥2-yx≤2+y∴2-y≤x≤2+y4-2y≤2x≤4+2y4-3y≤2x-y≤4+y∵0≤y≤3∴-3≤-y≤0-9≤-3y≤