math problem solving. How many soft books

Question

Larkin went to a garage sale and spent $5.75 on books .50 for hard cover and .25 for soft cover. She bought 17 books in total. How many soft cover books did she buy?

Answer 1

Let's have h be # of hard cover books, and k be # of soft cover books.

 

h+k = 17

Value equation: 0.5h + 0.25k = 17.5 ($)

 

You can solve this system by a simple substitution.  Proceed (and check your answers).