If the number of downloads of the standard version is x, and the high quality is x, 2.1*x+4.1*y=2761 (not 1010 due to that this is multiplied by 2.1 and 4.1, therefore representing the total amount of megabytes) In addition, there are 1010 total downloads, and it's either 2.1 MB or 4.1 MB, so x+y=1010.
We have
2.1x+4.1y=2761
x+y=1010
Multiplying the second equation by -2.1 and adding it to the first equation, we get 2y=2761-1010*2.1=640 and by dividing both sides by 2 we get y=320 downloads of the high quality version
CD = XY = 26 mm
hope that helps
I thought this would be simple, as I'm familiar with algebra and not really "The constant of proportionality," but I will do my best.
So this said "Constant of proportionality," is referring to basically the answers for the equation when X equals certain numbers.
Make a table of different answers when you plug in X and you get the 'Constant of proportionality.'
y = 2.5x + 3
y = 2.5(1) + 3
y = 2.5 + 3
y = 5.5
Since we plugged in 1 for X and got 5.5 for Y, our input and output is (1, 5.5)
Replace X for a different value, and you will get a bunch of different numbers that will in essence be your function inputs and outputs. Make a table of these and you have your answer.
EXAMPLE -
-= x =- -= y =-
-= 1 =- -= 5.5 =-
-= 2 =- -= 8 =-
-= 3 =- -= 11.5 =-
-= 4 =- -= 13 =-
So there you have it. I hope this helps! If you have any further questions, don't hesitate to ask.