Which expression has an answer of 18?

Use the order of operations and try every option. The first option results in 14 since 2 . 5 = 10, then 10 + 4 = 14. This does not work. The second option does result in 18. The numbers in parentheses are added first and result in 9, which is then multiplied through 2 to get a final answer of 18. Choice c does not work since the operation in parentheses is completed first, yielding 6, that are then multiplied through 5 to get a result of 30. Choice d does not work since the multiplication is done first, yielding 8, which is added to 5 for a final answer of 13.