Объяснение:
https://onlinemektep.org/schedule/25.12.2020/lesson/ehttps://onlinemektep.org/schedule/25.12.2020/lesson/e4f1151e-fd2e-41f8-9364-7de28b894b77/conference4f1151e-fd2e-41f8-9364-7de28b894b7https://onlinemektep.org/schedule/25.12.2020/lesson/e4f1151e-fd2e-41f8-9364-7de28b894b77/conference7/conferencehttps://onlinemektep.org/schedule/25.12.2020/lesson/e4f1151e-fd2e-41f8-9364-7de28b894b77/conferencehttps://onlinemektep.org/schedule/25.12.2020/lesson/e4f1151e-fd2e-41f8-9364-7de28b894b77/conference
здесь х=t - время (?)
Уравнение скорости v(t)=-16+10t, тогда v(t)=9=-16+10t, t=25/10= 2.5c