( + 4)(
- 4)
To solve this question you must FOIL (First, Outside, Inside, Last) like so
First:
(x^2 + 4)(x^2 - 4)
x^2 * x^2
x^4
Outside:
(x^2 + 4)(x^2 - 4)
x^2 * -4
-4x^2
Inside:
(x^2 + 4)(x^2 - 4)
4 * x^2
4x^2
Last:
(x^2 + 4)(x^2 - 4)
4 * -4
-16
Now combine all the products of the FOIL together like so...
x^4 - 4x^2 +4x^2 - 16
Combine like terms:
x^4 - 4x^2 +4x^2 - 16
- 4x^2 +4x^2 = 0
x^4 - 16 <<<This is your answer
Hope this helped!
~Just a girl in love with Shawn Mendes
Answer:
Check the explanation
Step-by-step explanation:
Since each and every one of the 4 hallways is equally likely then
Now, if he chooses H1 he escapes after 12 minutes then
If he chooses H2 then he wastes 10 minutes and then he is again in the same starting
position so he expects to escape in E(T) minutes, then
Analogously, if he chooses H3 then he wastes 40 minutes and then he is again in the same starting
position so he expects to escape in E(T) minutes, then
Therefore
So we have
Therefore he is expected to escape in 72 minutes