 |
| ||
| |||
|
| Math Central | Quandaries & Queries |
|
Question from Jay: When calculating percentage growth, why is (y-x)/x the same as (y/x)-1 ??? (I seem to be stuck on the simple algebra here)... e.g. 2011, toy was £5, 2012, toy is £10. What is the percentage increase? So, (10-5)/5 = 1 (i.e. 100% increase), AND, (10/5)-1 = 1 (i.e. also 100% increase). Thanks in advance. |
Hi Jay,
Write $1 = \large \frac{x}{x}$ and then
\[\frac{y}{x} - 1 = \frac{y}{x} -\frac{x}{x} = \frac{y - x}{x}\]
I hope this helps,
Penny
| ||
| ||
| ||
 |
 |
|
Math Central is supported by the University of Regina and The Pacific Institute for the Mathematical Sciences.