Simplify-3(4a-5b)-(a-b)

Find the given elements if matrix d:

Beth makes batches of bluberry muffins and banna muffins. each batchis 6 muffins. she makes 2.5 batches of bluberry muffins. how many batches of bananna muffins should beth make if she wants to have a total of 60 muffins?

Me with this one question, and i'll upvote the brainliest answer