"Because you do not know algebra," replied Barbicane tranquilly.
"Ah, that's just like you dealers in x! You think you have explained everything when you have said 'algebra.'"
"Michel," replied Barbicane, "do you think it possible to forge without a hammer, or to plough without a ploughshare?"
"It would be difficult."
"Well, then, algebra is a tool like a plough or a hammer, and a good tool for any one who knows how to use it."
"Seriously?"
"Quite."
"Could you use that tool before me?"
"If it would interest you."
"And could you show me how they calculated the initial speed of our vehicle?"