5x - 2. Just combine like terms, and distribute the + to the second term.
5(a-1) - 15 = 3(a+2) + 4
Open all parenthesis and distribute
5a - 5 - 15 = 3a + 6 + 4
Simplify
5a - 20 = 3a + 10
Add both sides by 20 and subtract both sides by 3a
2a = 30
a = 15
let 'x' represent the number of all the passes for the year
350 passes = 70% of all the passes
350 passes = 70% of x
0.70x = 350
by solving we find:
x = 500 passes
Answer:
about 7.6 days long
Step-by-step explanation:
42 divided by 5.52 = about 7.6
Answer:
![(D)E[ X ] =np.](https://tex.z-dn.net/?f=%28D%29E%5B%20X%20%5D%20%3Dnp.)
Step-by-step explanation:
Given a binomial experiment with n trials and probability of success p,


Since each term of the summation is multiplied by x, the value of the term corresponding to x = 0 will be 0. Therefore the expected value becomes:

Now,

Substituting,

Factoring out the n and one p from the above expression:

Representing k=x-1 in the above gives us:

This can then be written by the Binomial Formula as:
![E[ X ] = (np) (p +(1 - p))^{n -1 }= np.](https://tex.z-dn.net/?f=E%5B%20X%20%5D%20%3D%20%28np%29%20%28p%20%2B%281%20-%20p%29%29%5E%7Bn%20-1%20%7D%3D%20np.)