Question

Solve for L.
P=2L+2W

In this format
L=(__)/__

Anybody know how to do this?

Answer 1

This is more common than you believe.
You see, in mathematics, when we put a letter instead of a number we mean "Any real number", so "P","L" and "W" are actually any number you wish them to be, that is called a "variable".

Now, when we are stated a problem with only variables and asked to solve for one, we'll just solve and treat them all except the desired variable as numbers, and leave it as an answer.
Si if we have:
\[P=\frac{ 2L }{ 2W }\]
We can see that "2" is repeated on the numerator and denominator, and they are multiplying so we can separate them like this:
\[P=(\frac{ 2 }{ 2 })(\frac{ L }{ W })\]
"2/2" is equal to 1.
So we would just work with "L/W".
\[P=\frac{ L }{ W }\]
Since we are asked to solve only for L, wich means we must isolate it on the right side, we'll multiply both sides by "W" and we would isolate it:
\[WP=L\]
So we can conclude that:
\[L=WP\]
And that solves the problem.