Brianna and Luis ave several pairs of athletic shoes. Brianna has 4 pairs of athletic shoes, and Luis has x pairs of athletic shoes. They have a total of 11 pairs of athletic shoes between the two of them. Write an equation to describe this situation.
4+x=11, this is because you have to add the pair of shoes Brianna has to the "x" amount of shoes Luis has causing it to equal 11 pair of shoes in total as stated in the problem above.