Answer:
About 6.32 hours.
Explanation:
P= production
t=# of hours needed
How many hours are needed to reach the production level of 400?
Plug the numbers into the formula given.
400=300+50 ( t-10 squared)
Combine like terms- 400=350 (t-10 squared)
subtract 350 from itself, then do the same to the other side.
400-350=350-350(t=-10 squared)
50= (t-10squared)
50-10= 40 squared
40 squared= about 6.32.
Hope this helps! Have a nice day :)