Use the depreciation formula.

Where 'p' is the principal value, 'r' is the rate it depreciates, and 'n' is the time. Just plug in what we know:

Simplify by subtracting:

Simplify the exponent:

Multiply:
The answer for your problem (1) is 7.41
Answer:
y= 5 x= 2
Step-by-step explanation:
-3x+5y=2x+3y
5y=5x+3y
2y=5x
I think its 31 but im not 100% sure :)
He has 24 books! 2 dvds for every 8 books equals 1 dvd for every 4 books. 6 dvds times 4 books (6x4) equals 24.