Given:
The given quadratic equation is

or, 
And
The roots are given: 
To find the missing step.
Let us solve the equation.

or, 
or,
[ eliminating 16 from both the side]
or, 
or, 
or, 
Hence,
The step 2 could be 
Since p=q/w or percent equals quatity divided by whole, u have to divid 12.2 by 12.25
883.6 ......................