I really need this answer

Which is an equation for the nth terms of the sequence 12,15,18,21

Emma will roll two number cubes labeled 1 through 6. she will record the sum of the two numbers after each roll. she will roll the two cubes 540 times. how many times should emma expect the sum to equal 5?

Find the product of (4x + 3y)(4x − 3y). 16x2 − 24xy + 9y2 16x2 − 9y2 16x2 + 24xy + 9y2 16x2 + 9y2