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
Steps 4 and 5 are being used to get the equation in step 6.
Steps 5 and 7 are being used to get the equation in step 8.
Steps 8 and 6 are being used to get the equation in step 9.
In step 14, "similar argument" means to draw segment BD and follow the same logic in steps 3-12.
Percent means parts out of 100
30%=30/100=3/10
'of' means multiply
60 is 30% of what translates to
60=3/10 times what
multiply both sides by 10/3
600/3=what
200=what
the number is 200
The vertex of the quadratic equation is (-5, - 28). In vertex form, y = a(x - h)2<span> + </span><span>k, (h, k) is the vertex of the equation.</span>
Answer: -72a^3 +108a^2
Collect like terms
(2a)(6a)(2a-8a+9)= (2a)(6a)(-6a+9)=12a^2(-6a+9)
= -72a^3 +108a^2
