Question 153482
There are 7 days you can either pick in Tampa or Orlando.
Let's call the number of days in Tampa, T, and the number of days in Orlando, R.
We know 
1.{{{T+R=7}}}
We also know that we have to meet the $2300 budget. 
Each day in Tampa cost $275/day. 
The total cost is the number of days in Tampa multiplied by 275 or 275*T
Each day in Orlando cost $400/day. 
The total cost is the number of days in Orlando multiplied by 400 or 400*R,.
The grand total equals $2300.
2.{{{275*T+400*R=2300}}}
Use eq.1 to solve for R as a function of T.
1.{{{T+R=7}}}
{{{R=7-T}}}
Now substitute this expression into 2.
2.{{{275*T+400*R=2300}}}
{{{275*T+400*(7-T)=2300}}}
{{{275*T+2800-400T=2300}}}
{{{-125T=-500}}}
{{{T=4}}}
Since
{{{R=7-T}}}
{{{R=3}}}
4 days in Tampa, 3 days in Orlando.