The answer to the following equation is the first one.
Answer:
4
Step-by-step explanation:
4(4-4)+4=4
insert 2 in a and-2 in b
Answer:
2xy+10z-5yz-4x
Step-by-step explanation:
Just put the positives and negatives together. You can't add or subtract any of them because they aren't like terms.
If you are travelling at 65 mph, you have to think of it as if you are moving at a constant speed. By dividing 65 by 60, you are calculating how many miles you are moving each minute. In doing so, you can calculate that you are moving at 1.083333 miles each minute. That's approximately 5720 feet per minute. (This is calculated by multiplying 1.083333 by 5280 (the number of feet in a mile)). 5720 x 22 minutes, you will have traveled 125,840 feet.
Hope this helps!
Answer:
5.78% probability that exactly 2 of them use their smartphones in meetings or classes.
Step-by-step explanation:
For each adult, there are only two possible outcomes. Either they use their smarthphone in meetings or classes, or they do not. The probability of an adult using their smartphone on meetings or classes is independent of other adults. So we use the binomial probability distribution to solve this question.
Binomial probability distribution
The binomial probability is the probability of exactly x successes on n repeated trials, and X can only have two outcomes.

In which
is the number of different combinations of x objects from a set of n elements, given by the following formula.

And p is the probability of X happening.
63% use them in meetings or classes.
This means that 
7 adult smartphone users are randomly selected
This means that 
Find the probability that exactly 2 of them use their smartphones in meetings or classes.
This is P(X = 2).


5.78% probability that exactly 2 of them use their smartphones in meetings or classes.