B. (k+10f)(k-5f) you can tell in 2 ways. 1. if the second sign is neg then the signs in the factors are going to be one neg and one positive so that knocks out C and D. Then you look at the second term and since the 5 is positive then the 10 has to be positive so you end up with a positive 5kf.
The second way is to FOIL them out. When you check B you get

combine your like terms and you have your original expression of

Hope that helps
Answer:
3 X 52 =156
100+6.5 = 106.5, 106.5/100 = 1.065
1250 X 1.065^156 = 23091323.5
$23091323.50
Answer:
a) 2/3
b) 1/3
Step-by-step explanation:
Let X be the random event that measures the time you will have to wait.
Since time is uniformly distributed between 10 and 10:30 in intervals of 1 minute
P(n < X ≤ n+1) = 1/30 for every minute n=0,1,...29.
a)
P( X > 10) = 1 - P(X ≤ 10) = 1 - 10/30 = 2/3
b)
P(10 < X ≤ 20) = (20-10)/30 = 1/3