Recall the binomial theorem.

1. The binomial expansion of
is

Observe that


When we multiply these by
,
•
and
combine to make 
•
and
combine to make 
and the sum of these terms is

2. The binomial expansion is

We get the
term when
:

Answer:
Step-by-step explanation:
a) together, they all drink about 2,090 glasses of water in one day. (418 * 5 = 2,090).
b) 2,090 * 7 (7 days in 1 week) = They drink about 14,630 glasses of water in one week.
c) 14,630 * 4 (4 weeks in 1 month) = About 58,520 glasses of water in one month.
d) 1,000,000/58,520 ≈ 17. It would take all of the students about 17 months to drink 1,000,000 glasses of water.
Hope that helps!
Answer:
5.5
Step-by-step explanation:
2,3,3,4,5,7,8,8,8,10,10,12
The mean of this data is 7.5. So what you are trying to figure out is the mean between 2 and 7. Since that is 3 and 4 it would be 3.5. So 3.5 is the Q1. Now you have to figure out the mean between 8 and 12. That is 9. This is Q3. You have to subtract 9-3.5 and that is the interquartile range. So 5.5 is the answer. I hope that made sense.
Hey there!
Apply fraction cross multiply: if a/b = c/d , then a *d = b*c
2 ( 5x - 2 ) = ( 2x + 4 ) * 4
expand : 2 (5x-2 ) => 2*5x - 2*2 => 10x - 4
expand : ( 2x +4 ) * 4 => 2x * 4 + 4*4 => 8x + 16
10x - 4 = 8x+16
add 4 to both sides:
10x-4+4 = 8x+16+4
simplify :
10x = 8x + 20
subtract 8x from both sides:
10x -8x = 8x+20-8x
simplify:
2x = 20
Therefore:
x = 20 / 2
x = 10
Hope that helps!