Answer:
20 hours
Step-by-step explanation:
If your computer can download a movie in 5 hours, then it downloads [tex]\frac{1}{5}[/tex] of a movie in 1 hour.
The extra processor in 1 hour, reduces the time down to 5 hours, so it downloads [tex]\frac{1}{4}[/tex] of the movie in 1 hour.
The time that the extra processor will spend to download a whole movie added to [tex]\frac{1}{5}[/tex] will equal [tex]\frac{1}{4}[/tex] .
So our equation is [tex]\frac{1}{5} + \frac{1}{x} = \frac{1}{4}[/tex].
To simplify this, lets multiply all sides by 20x.
[tex](\frac{1}{5}+\frac{1}{x} \cdot 20x) = \frac{1}{4}\cdot20x\\ 4x + 20 = 5x[/tex]
Now we can simplify this equation.
[tex]20 = 5x-4x\\\\20 = x\\x = 20[/tex]
So the extra processor alone would take 20 hours to download the movie.
Hope this helped!
