First line because 4(2a+1)=8a+4 and 9a+4-(8a+4)= a
Second line because a times 2 =2a and 2a+1-2a=1
<span>Although the second equality is more or less obvious since 2a+1 leaves a remainder of 1 when divided by a.</span>
If you take 2000 and subtract that by 500 for the childrens books that would equal 1500. So, the fiction and nonfiction books sum would have to be 1500. Since 850 plus 650 equals 1500, there would be 650 nonfiction books, 850 fiction books, and 500 children's books.
Hope This Helps!
Answer:1547.9 miles per hour
Step-by-step explanation:
Let the two trains leave in x direction and y direction
Velocity of train in x direction be v
therefore velocity of train in Y direction is v+29
because one train is 29 miles per hour slower than other.
Distance travel by train in x direction is(x) v(2)
Distance travel by train in y direction is(y) 2(v+29)
distance between them after 2 hours is 4420 miles
Now using pythagoras theorem


on solving

v=
v=1547.889 miles per hour
The mean of the discrete probability distribution is of 1.28.
<h3>What is the mean of a discrete distribution?</h3>
The expected value of a discrete distribution is given by the <u>sum of each outcome multiplied by it's respective probability</u>.
Then, considering the given distribution, the mean is given by:
E(X) = 0(0.13) + 1(0.61) + 2(0.15) + 3(0.07) + 4(0.04) = 1.28.
More can be learned about the mean of a discrete probability distribution at brainly.com/question/24855677
Is this supposed to be a matching game of some sort? If so, I don’t think any of these here match what’s in the tables.
Sorry :(