Can somebody help me find y

An arithmetic series a consists of consecutive integers that are multiples of 4 what is the sum of the first 9 terms of this sequence if the first term is 0

You're locked out of your house. the only open window is on the second floor, 25 feet above the ground. there are bushes along the edge of the house, so you will need to place the ladder 10 feet from the house. what length ladder do you need to reach the window?

Atriangle in the coordinates of (2,3), (-4,5) and (-2,4) it is translated 3 units down. what are it’s new coordinates