-3n+48=0
-3n=-48
-3n/-3 & -48/-3
n=16
Answer:
C. 
Step-by-step explanation:
I think the equation meant
?
Anyways, to factor these kinds of quadratic, keep into consideration:

ONLY if:

Start off by finding factors of c, which in this case, -18:
±(1, 2, 3, 6, 9, 18)
If one of the numbers is negative then the other number must be positive.
Find which two factors will sum up to b, which in this case, is 3.

The only two factors that work are 6 and -3.
Replace them into the factored form:

Answer: 0.3439
Step-by-step explanation:
Given :The last four digits for telephone numbers are randomly selected (with replacement).
Here , each position can be occupied with any of the digit independently .
Total digits = 10
Total digits other than 0 = 9
For each digits , the probability that it is not 0 = 
If we select 4 digits , The probability of getting no 0 =
(By multiplication rule of independent events)
Now , the probability that for one such phone number, the last four digits include at least one 0. = 1- P(none of them is 0)
=1- 0.6561=0.3439
Hence, the probability that for one such phone number, the last four digits include at least one 0. is 0.3439 .
It will be 48/52 because there are 4 kings so 52-4=48