Answer:
11
Step-by-step explanation:
15 - 4 = 11
D(t) = -4t^3 + 40t^2 + 500t = 4088
4t^3 - 40t^2 - 500t + 4088 = 0
t = 7
Therefore, the plane has flown 4088 km 7 hours after it took off.
Answer:
2
Step-by-step explanation:
we have:
-11-(-13)
-11 +13
2
The answer is
.
Solution:
Use algebraic identity: 
For example: 
Given expression
and
.
To multiply these equations.




Combine like terms together.



Hence the answer is
.