Marie is buying light bulbs for her Christmas decorations. She buys but when she gets to the cash, she has to put back four because they are broken. How many light bulbs does Marie buy?

This is what i found “an explicit formula designates the nth term of the sequence, as an expression of n (where n = the term's location). it defines the sequence as a formula in terms of n. this example is an arithmetic sequence(the same number, 5, is added to each term to get to the next term).” i hope this you for what your looking for. can you plz mark me brainliest?