Sometimes you have a formula,
such as something from geometry,
and you need to solve for some variable other than the "standard"
one. For instance, the formula for the perimeter P of a square with sides of length s is P = 4s.
You might need to solve this equation for s,
so you can plug in a perimeter and figure out the side length.
This process of solving
a formula for a given variable is called "solving literal equations".
One of the dictionary definitions of "literal" is "related
to or being comprised of letters", and variables are sometimes referred
to as literals. So "solving literal equations" seems to be another
way of saying "taking an equation with lots of letters, and solving
for one letter in particular."
At first glance, these
exercises appear to be much worse than your usual solving exercises, but
they really aren't that bad. You pretty much do what you've done all along
for solving
linear equations<span> and other sorts of equation; the only substantial difference is that,
due to all the variables, you won't be able to simplify your answers
as much as you're used to. </span>