Question

как по формуле m1U1 + m2U2 = (m1 + m2)U найти U2?

Answer 1

$m_1u_1+m_2u_2 = (m_1+m_2)u \ m_2u_2 = (m_1+m_2)u - m_1u_1\\ u_2 = frac{(m_1+m_2)u - m_1u_1}{m_2} = u - frac{m_1}{m_2}(u-u_1)$