Answer:
He can buy 28 books or less.
Explanation:
ox will represent the number of books he can buy. He can only use $230 or less. I am going to use <, but It's supposed to be less than or equal, not less than, so make sure to put a less-than sign with a line under it.
90+5x<230 Subtract 90.
5x<140 Divide by 5.
x<28 This means that he can buy 28 or fewer/less books.