How do I solve this arithmetic sequence?

Write the summation to estimate the area under the curve y = 1 + x2 from x = -1 to x = 2 using 3 rectangles and right endpoints

Sasha delivers newspapers to subscribers that live within a 4 block radius of her house. sasha's house is located at point (0, -1). points a, b, c, d, and e represent the houses of some of the subscribers to the newspaper. to which houses does sasha deliver newspapers?

Astock has a 25% probability of increasing by $10 and a 75% probability of decreasing by $5. what is the stocks expected increase or decrease?