упростите выражения
1) m-t/m+t - m+t/m-t
2) (m+t)(m-t)-m(m-2t)

1) m-t/m+t - m+t/m-t = (m-t)^2 - (m+t)^2/m^2 - t^2 = m^2 - 2mt + t^2 - m^2 - 2mt - t^2/m^2 - t^2 = - 4mt/m^2 - t^2

2)(m+t)(m-t)-m(m-2t) = m^2 - t^2 - m^2 + mt = -t^2 + mt = t(m - t)