Answer:
a^3-b^3
Step-by-step explanation:
(a−b)(a2+ab+b2)
=(a+−b)(a2+ab+b2)
=(a)(a2)+(a)(ab)+(a)(b2)+(−b)(a2)+(−b)(ab)+(−b)(b2)
=a3+a2b+ab2−a2b−ab2−b3
=a3−b3
Answer:
Expected time is 15 hours for him to get to safety.
Step-by-step explanation:
We define X as the time that this miner would get to safety.
We define Y as the door he chooses initially.
P(Y= 1) = P(Y=2)=P(Y=3) = 1/3
We have E[X|Y=1] = 3
E[X|Y] = 5 hours + E[X}
E[X|Y] = 7 hours + E[X]
Then we have
E[X] = 1/3(3 + 5 + E[X] + 7 + E[X])
We cross multiply
3*E[X] = (15 + 2E[x])
3E[X] - 2E[X] = 15
E[X] = 15
So the time it would take to get him to safety is 15 hours
Answer: y = 7
Explanation:
7^8/7y = 7^6
7^7/y = 7^6
In order for 7^7 to become 7^6 you need to divide by 7
Which mean y = 7
So that:
7^7/7= 7^6
7^6 = 7^6
-√5/2+√5+1
-√5/2+2√5/2+1
√5/2+1
(√5+2)/2
She needs 700 milliliters more. 700 ml is 0.7 liters
