Answer:
it's potential energy decreases
To get the mean distance that Jim jogged, you have to solve
for the total miles he was able to jogged divided by the number of days he
jogged.
6.5 miles + 5 miles + 3 miles + 2 miles + 3.5 miles + 4
miles = 24 miles / 6 days = 4
Therefore, the mean distance that Jim jogged is 4 miles.
Let x be the mass of the paperbacks and y be the mass of the textbook.
20x + 9y = 44.4 ----------- (1)
25x + 10y = 51 -------------(2)
(1) x 10:
200x + 90y = 444 --------(1a)
(2) x 9:
225x + 90y = 459 --------(2a)
(2a) - (1a):
25x = 15
x = 0.6 -------- sub into (1)
20 (0.6) + 9y = 44.4
12 + 9y = 44.4
9y = 44.4 - 12
9y = 32.4
y = 3.6
So the paperback's mass is 0.6 pounds and textbook is 3.6 pounds
He will spend $66.3 because 78 times 15/100 (which is 15%) is 11.7, and since he reduces the food you will have to subtract 11.7 from $78, to get $66.3