Grace bought a book for $8 and some pencils that cost $.50 each. she spent a total of $18. write and solve an equation to determine how many pencils she bought. let p represent the number of pencils she bought.

brian sold half of his baseball cards. the next day, he bought 10 more. now he has a total of 50 cards. write and solve an equation to determine how many baseball cards he had before he sold any. let b represent the number of baseball cards he had.