Пуля массой m ,летящая горизонтально,попадает в шар массой М и застревает в нем .Длина нити равна L .при какой скорости пули шар сможет описать четверть окружности?

Даны две окружности, радиуса 16 и 19, которые касаются в точке А. К окружностям проведена общая касательная, которая касается окружностей в точках В и С , проведена общая касательная которая проходит через точку А и пересекает касательную ВС в точке К. Найти отрезок АК.

Переведите текст, пожалуйста! The continuously growing army of pupils at general public schools requires more teachers. The demand for teachers is particularly great now in connection with the transition to general complete secondary education. The country is therefore increasing admittance to higher and secondary pedagogical schools. Much attention is being paid to training teachers from non-Russians. Great opportunities have been provided for training teachers in physics, mathematics, drawing, mechanical drawing and physical training. Pedagogical institutes train students to teach one subject. Only a few institutes train teachers in two related subjects. The schoolteachers who have no diplomas of higher pedagogical education are provided with ample opportunity to acquire it without having to discontinue their work. All teachers employed at public schools, as well as the schools management, may attend advanced courses. For instance, in 1966/1967 academic year, as in previous years, these courses were run by school methodological councils, district (city) methodological centers, regional. The pedagogical societies which have been established in the Russian Federation and some of the other Union Republics have aroused among teachers a creative approach to their work. Soviet teachers are highly respected. They take an active part in public affairs; they conduct extensive cultural educational campaigns among the Soviet population.

Разложите на множители выражение: (x-3)(x+2)+2(2x+1)