The hard part here is taking all this info and making into equations you can work with.

Let x be the number of jeans sold and y be the number of shirts sold. Then for the first day:

I just dropped the dollar signs off the prices for convenience. So that means that 25 dollars times the number of jeans sold plus 18 dollars times the number of shirts sold totaled 441 dollars for the day.

Now for day two. This time, the price of both items is 20 dollars.

That is done by the same logic as the first equation. Also, we can use the same x and y from the first equation because the problem said the same amount of each item was sold.

Now you have two equations and two variables and hopefully you can take it from here.