Question

Jane buys two books for `$72`. One is `3` times the price of the other plus `$4`. What are the prices of the two books?

Answer 1

Call the price of the cheaper book `P`, then the price of the more expensive book is `3P+4`. Together, `P+3P+4=72`, which means `4P+4=72`, so `4P=68`, so `P=$17`. The price of the other book is `3(17)+4=$55`.