Question

выразите m2
m1u1+m2u2=(m1+m2)u

Answer 1

если это m второе, то
m1u +m2u2 = (m+m2)*u
m2u2 = mu +m2u - m1u
m2u2 - m2u = mu - m1u
m2 (u2-u) = mu - m1u
m2 = (mu - m1u) / u2 - u