Let

the cost of a DVD
Let

the cost of a CD
We have

and

We can replace

with

in the second equation and get



False
Most photographers become photographers initially because they have a passion for taking photos but if you claim to be a photographer that implies that you do this for a living and you do it professionally meaning that you are taking photos for money.
I honestly don't know, but my best guess would be the highly concentration salt solution because usually salt dehydrates things.