Each case of orange has "x" oranges inside, therefore to determine how many oranges each person is selling we need to multiply the number of cases by "x". With this in mind let's complete the problem.
The first drop-down menu is "Eleanor sells ..." we need to choose the option "7*x", because he sells 7 cases with x oranges each.
The second drop-down menu is "Raul sells ..." we need to choose the option "10*x" because he sells 10 cases with x oranges each.
The third drop down menu is "the equivalent expression ..." we need to choose the option "7*x + 10*x=17*x".
The fourth drop down menu is "The ... property" we need to choose distributive.
The fith drop down menu is "the equivalent expression" we need to choose x(7+10).
The last drop down menu is "to the equivalent expression" we need to choose 17x.