Answer:
I asked my teacher if we could use that she said it's considered cheating, I still use it
Step-by-step explanation:
c square
its making me write 20 more characters
ignore this
the answer is c squared
Answer:
40/9
Step-by-step explanation:
Use the work formula, 
+ 
= 
, where A is the amount of time it takes one person, B is the amount of time it takes another person, and T is the time it takes for them to work together.
Plug in the times for David and Alex alone:
+ 
=
Find the least common denominator, which is 40.
+ 
=
=
Cross multiply and solve for T:
9T = 40
T = 40/9
So, if they worked together, it would take them 40/9 hours
The average can be calclculated as follows:
average = sum of number/number of numbers
average = (19+45) / 2 = 64/2 = 32
