Answer:
2.2
Step-by-step explanation:
discount per tshirt=(originalprice-discountedprice)/numberofshirtssold
20 tshirts
originaprice=20*p=20p
discountedprice=20p-60
numberofshirtssold=20
discountpershirt=(20p-(20p-60))/20
discountpershirt=(20p-20p+60)/20
discountpershirt=(60)/20
discountpershirt=3
the discount per tshirt is $3.00 per shirt
Answer: (13,-7)
Step-by-step explanation:
By using the formula 
is the coordinates of the midpoint.
For finding the midpoint X variable do:

For finding the midpoint Y variable do:
(you can either keep the parenthesis or take them out. Either way, the answer is the same.
Considering coordinate numbers follow the format: (x,y), you'll simply just substitute the numbers found above into their respective places.
x: 13
y: -7
(13,-7).
C - 7.6 = -4
c = -4 + 7.6
c = 3.6