Solution
For this case we can conclude that the correct equation for the profit would be given by:
2.25 x + 1.75 y = 115.25
Where x = number of cupcakes sold
y = number of brownies sold
And we can find the number of cupcakes sold like this:
x= (115.25 -1.75y)/2.25
And we can find the number of of brownies with this formula:
y= (115.25 - 2.25x)/1.75