Beverly has a bag of marbles that weighs 30 grams. She knows that each marble weighs 1.5 grams and the bag weighs 1.5 grams.

Which equation could she use to determine how many marbles are in the bag? Select all that apply.
(1.5)x + 1.5 = 30
30 – x = 2(1.5)
(1.5)(30) = 1.5x
1.5 + x = 30
1.5x = 30 – 1.5