Question

若（x^2-y^2分之M）=(x^2-y^2分之2xy-y^2)+(x+y分之x-y）,则M=多少

Answer 1

（x^2-y^2分之M）=(x^2-y^2分之2xy-y^2)+(x+y分之x-y）,

M/(x²-y²)=(2xy-y²)/(x-y)(x+y)+(x-y)/(x+y)

M/(x-y)(x+y)=(2xy-y²+x²-2xy+y²)/(x-y)(x+y)

M/(x-y)(x+y)=x²/(x-y)(x+y)

∴M=x²