15 less than twice a number in algebraic expression

Abiologist is recording the loss of fish in a pond. he notes the number of fish, f, in the pond on june 1. on july 1 there were 63 fish in the pond, which is 52 fewer fish than were in the pond on june 1. which equation represents this situation? a. f – 52 = 63 b. f – 63 = 52 c. 63 – f = 52 d. f – 63 = –52

Find the greatest common factor of -30x 4 yz 3 and 75x 4 z 2.

Any is very appreciated! (picture is provided below)not sure how to do this at all won't lie