Answer:
The age of the person who entered the room is 15
Step-by-step explanation:
We are given:
Ages of 5 people in a room are:
17, 16, 15, 17, 22
A person enters room, and then the mean age of 6 people is 17.
We need to find the age of person who entered the room.
The formula to calculate mean is: 
Now, in question we are given mean of 6 people that is 17
The age of 5 people are given while age of one person who enters the room is unknown.
Let age of person whose age is unknown= x
Now finding x using mean formula

So, The value of x: x=15
Hence, the age of the person who entered the room is 15
Answer:

Step-by-step explanation:

6(x-17) it is disturbing 6
it is 6x-102 or 6x-6.17
so the answer is C
Answer:
the answer is 6x^2
Step-by-step explanation:
goodluck
Answer and explanation:
Statement - If the difference of two numbers is even then so is their sum.
Let the two even numbers be '2m' and '2n' with m and n are integers.
The difference of two number is

Now, The sum of the numbers is

Let
where k is an integer
Then,
which is also an even number as 2 is multiplied with it.
So, If the difference of two numbers is even then so is their sum.
For example -
Let two even number 2 and 4.
The difference is
, 2 is even.
The sum is
, 6 is even.