The answer is -9+7 because it INCREASED which means adding ( + ).
I'm pretty sure if the answer accepts decimals, if two apples = 175 grams, then one apple equals 87.5 grams, and if we want an apple that equals four grams, it would be less than one apple so we would divide the grams of one apple till it equals 4, therefore 87.5/4 = 21.875
P.S. im not entirely sure this is right im just trying to help :)
Is is the first one. 1600=.45x
For every 3 seconds, the scuba diver dives 0.5 feet
after 15 seconds = your answer
3 x 5 = 15
0.5 x 5 = your answer
your answer = 2.5
2.5 is your answer
hope this helps