This sequence has generating function

(if we include
for a moment)
Recall that for
, we have

Take the derivative to get


Take the derivative again:


Take the derivative one more time:


so we have

The sum of their speeds is 380 miles per hour. The difference of their speeds is 30 miles per hour. Then the faster plane is traveling at
.. (380 +30)/2 = 205 miles per hour
The slower plane's speed is 30 miles per hour less, so it is traveling at
.. 205 mph -30 mph = 175 miles per hour
Answer:
b + g = 25
b = g + 3
Step-by-step explanation:
Let b = number of boys.
Let g = number of girls.
"Mrs. Smith has a total of 25 kids in her class."
b + g = 25
"There are 3 more boys than there are girls."
b = g + 3
The system of equations is:
b + g = 25
b = g + 3