Answer:
Answer: Third option is the right answer.
Step-by-step explanation:
First we the write the expression
Now teacher says that the product of these polynomials will result in the sum of 
Now the teacher ask if we put the value of a = 2x and b = 1 then what will be the expression look like.
![(2x+1)\left [ (2x)^{2}+(1^{2})-(2x)(1)\right ]](https://tex.z-dn.net/?f=%282x%2B1%29%5Cleft%20%5B%20%282x%29%5E%7B2%7D%2B%281%5E%7B2%7D%29-%282x%29%281%29%5Cright%20%5D)
=
So third option is looking like our expression.
Answer: 144 cubic feet
Step-by-step explanation:
Volume = base times height.
Base = 20 square feet
Height = 7.2 feet
Volume = 20 square feet * 7.2 feet = 144 cubic feet
I belive it would be B. because of the fact that they are parallel which means their slope should stay the same...but their y-intersept would change
Length of train : 100
length of bridge : 400
distance covered by the train to cross the bridge : (100 + 400) = 500
time taken by the train to cross : 30
speed = distance / time
speed = 500/30
speed = 16.67 meters per second <===
