# Literal Equations

• Feb 18th 2009, 07:10 PM
FlareHazard
Literal Equations
Could someone please tell me how to solve this problem?

Solve for w: P = 2l+2w

Thanks.
• Feb 18th 2009, 07:34 PM
Reckoner
Quote:

Originally Posted by FlareHazard
Could someone please tell me how to solve this problem?

Solve for w: P = 2l+2w

Thanks.

Simply write $\displaystyle w$ in terms of the other variables. This can be done using basic algebraic techniques.

I'll leave this particular problem for you to do on your own, but here's a similar example:

$\displaystyle \text{Solve for }p\!: y = 4px - 7z$

We want to get $\displaystyle p$ on one side by itself, and all the other variables on the other side. First we may add $\displaystyle 7z$ to both sides to get

$\displaystyle y{\color{red}\;+ 7z} = 4px - 7z{\color{red}\;+ 7z}$

$\displaystyle \Rightarrow y + 7z = 4px\Rightarrow 4px = y + 7z$

Now we can divide by $\displaystyle 4x$ to get

$\displaystyle \frac{4px}{\color{red}4x}=\frac{y+7z}{\color{red}4 x}$

$\displaystyle \Rightarrow p=\frac{y+7z}{4x},\;x\neq0$

$\displaystyle p$ is now in terms of $\displaystyle x,\;y$ and $\displaystyle z\text.$