A_{k o g u} = r m, η = \frac{A_{k a s u}}{A_{k o g u}}, A_{k a s u} = N t, t = \frac{s}{v}

${A_{kogu}=rm,\quad \eta=\frac{A_{kasu}}{A_{kogu}},\quad A_{kasu}=Nt,\quad t=\frac{s}{v}}$

Error