Answer:
<u>The number of pens = 120 and the number of pencils = 200</u>
Step-by-step explanation:
Let the number of pens x, and the number of pencils is y
the cost of one pen $1, and the cost of one pencil $0.5
The cost of the whole purchase was $220
1 * x + 0.5 * y = 220
x + 0.5 y = 220 ⇒ eq.(1)
there were 80 more pencils than pens
y - x = 80 ⇒ eq.(2)
from eq.(2) x = y - 80
By substitution with x from the last equation at eq.(1)
∴ (y - 80) + 0.5 y = 220
1.5y = 220 + 80 = 300
y = 300/1.5 = 200
x = y - 80 = 200 - 80 = 120
<u>So, the number of pens = 120 and the number of pencils = 200</u>
It is the last one since you must multiply all the sides to get volume.
Plz give brainliest
Amount charged for downloading individual songs = x dollars
Amount charged for downloading an entire song album = y dollars
Person A:
6x + 2y = 25.92
3x + y = 12.96
y = 12.96 - 3x
Person B:
4x + 3y = 33.93
Putting the value of y from the first equation in the second we get
x = 0.99 dollars
Putting the value of x in the first equation we get
y = 12.96 - 3x
= 12.96 - 2.97
= 9.99 dollars
Answer:
(a) 0.107 million per year
(b) 0.114 million per year
Step-by-step explanation:
(a) The average rate of change between 2000 and 2014 is determined by dividing the difference in the populations in the two years by the number of years. In the year 2000, 
and in 2014, 
. Mathematically,
(b) The instantaneous rate of change is determined by finding the differential derivative at that year.
The result of differentiating functions of the firm 
(where 
is a constant) is 
. Let's use in this in finding the derivative of 
.
In the year 2014, .
