Кто автор картины, на которой изображен мчащийся поезд?

решите уравнение :

[2х-1целая2/5]=[-2.5]

            Once a philosopher was traveling down a river in a small boat. While he 1_________________(cross) the river he2___________________(ask) the boatman:” You ever 3__________________(hear) about Philosophy?” “No”, 4__________________(say) the boatman. “I never 5_________________(hear) about it. What it 6__________(be)?” “I 7________________(be) sorry for you, indeed,” replied the learned man, “you 8________________(lose) a quarter of your life as it’s a very interesting science!” Several minutes later the philosopher asked the boatman another question: “You 9__________________(hear) about Astronomy, when you 10_____________(be) at school?” “No, I11_______________(leave) school many years ago and I 12________________________(forget) all about it.,” was the answer. To this the philosopher answered that he 13)__________________(be) really sorry for the man, and he 14_________________(think) that the boatman15_________________(lose) a second quarter of his life.

            Some minutes passed and the passenger again 16____________________(wonder) if the man ever 17__________________(hear) about Algebra. And the man 18______________(have to) admit that he never 19___________________(know) anything about it. “In that case you certainly 20_________________(lose) a third quarter of your life!” said the scientist.

            At that very moment the boat struck on a big stone. The boatman jumped and cried: “You ever 21_______________(learn)22_________________(swim)?” “No,” was the answer. The boatman explained sadly to the philosopher that he 23_______________(be) sure the scientist 24________________(lose) his whole life as the boat 25________________________(sink).

Найдите f(0). если f(x)=x^2-9 подробней!!!