Find the sum of x and y, if the following quadratic equations in x and y are true.

Two people go to the same store and make the same purchases, but one of them is treated unfairly in the pricing

Rational expressions word problem

The sum of two numbers is six more than twice the smaller number, and if the larger number is multiplied by three, the result is ten less than seven...

A problem involving the number of words in seven books on a shelf - arithmetic sequences

A hypothetical problem in which the treasury introduces a new coin into circulation

Two time-based arithmetic series combined at different rates

Determine how many floors a skyscraper has, based on information about someone climbing the stairs