What is the explicit formula for the arithmetic sequence –7.5, –9, –10.5, –12,

Idon’t understand this.. will someone ? will mark brainliest along with 20 points.

Gretchen is setting up for a banquet. she has 300 chairs and needs to distribute them evenly among t tables. how many chairs should she put at each table? write your answer as an expression.

Find the area of a parallelogram with the given vertices. p(-2, -5), q(9, -5), r(1, 5), s(12, 5)