Can someone answer this for me ?

Oliver had $50 on the day before his birthday. after he recived some money for his birthday , he had $75. write and solve eqaution to find how much money oliver received for his birthday. x+50=75

Sioux co. replaced the roof on its existing building, therefore increasing the building's life by 10 years. the cost of the roof is considered a(n):

Find the sum of the given arithmetic series. 24 + 17 + 10 + 3 + + (–39)