Quy đồng mẫu thức ba phân thức x/(x^2 - 2xy + y^2 - z^2); y/(y^2 - 2zy + z^2 -x^2)
Giải thích
x2-2xy+y2-z2=x-y2-z2 = (x – y + z)(x – y − z)
y2-2yz+z2-x2=y-z2-x2 = (y – z + x)(y – z − x) = -(x +y – z)(x – y + z)
z2-2zx+x2-y2=z-x2-y2 = (z – x + y)(z – x -y) = (x- y –z).(x + y – z)
MTC = (x – y + z)(x + y − z)(x – y − z)
