STEVE'S MATH PAGE
there is no missing dollar. Adding $27 and $2 to get $29 is an
irrelevant operation. They paid $27 - $2 went to the dishonest waiter,
and $25 went to the restaurant.
problem here is that every positive number has two square roots - one
positive and one negative. The last step, if correct, would read :
this is true. You can check:
A Limerick by Jon Saxton.
The outer circle has one-to-one contact with the surface. The
inner circle does not have one-to-one contact with the dotted line. It
slides and turns at the same time.