Thực hiện phép tính: a) x +y/ y -x : x^2 +xy/ 3x^2 -3y^2 ;
Giải thích
a) x+yy−x:x2+xy3x2−3y2=x+yy−x:x(x+y)3(x+y)(x−y)
=−x+yx−y:x3(x−y)=−x+yx−y . 3(x−y)x
=−3(x−y)(x+y)x(x−y)=−3(x+y)x;
a) x+yy−x:x2+xy3x2−3y2=x+yy−x:x(x+y)3(x+y)(x−y)
=−x+yx−y:x3(x−y)=−x+yx−y . 3(x−y)x
=−3(x−y)(x+y)x(x−y)=−3(x+y)x;