Can someone Help me out.

Step-by-step explanation:So you know Sara had $211 total to spend on her books, so we can set our equation equal to $211. You also know she bought 6 books but you don't know what they each cost. We can assume that they cost the same amount, so we can define this as 6x because you know you bought six books for some unknown amount of money. We also know she didn't spend $13 of the dollars, so we can think that she actually only spend $198 (211-13) on books.

So our equation would look like:

$211 = 13 + 6x   We subtract 13 from each side to solve for x

-13       -13

198 = 6x             We divide each side by 6 to get x alone because any number over itself is 1

 6       6

x = $33               Solve. So Sara spend $33 for each