4 - (-13) = 17
Hope this helps!
B. 1/40…. You divide 1/2 by 20 to find out how much hand sanitizer was used on each desk. You can keep change flip meaning keep the 1/2 change the division to multiplication and flip the 20 to 1/20 then multiply. 1/2 by 1/20 which equals 1/40.
Answer:

Step-by-step explanation:
we know that
The equation of a exponential growth is equal to

where
a is the initial value
r is the rate of growth
x is the time in hours
y is the value of the quantity
we have

substitute


For x=22 hours
substitute

The answer is 825
hope i could help you
A. 5x - 6 ................