To calculate the total price after applying the sales tax, we just need to apply the sales tax to the final values of the items.
Let x be how much she can spent on items.
To apply 5% in x, this means we want to calculate the total value plus 5%, that is, 105%.
So, we can multiply x by 105%.
However, we need to do this with the percentage in the decimal form:
So, the value of x after the sales tax will be:
Since she has 80, this final price can be at most 80, so:
Now, we just need to solve it.
To do it, let's first switch the sides so the variable x is to the left:
Now, we can divide both sides by 1.05 so that we nd up with only x on the left side:
So, she can spend approximately $76.19 on items.