Answer:
The sales price of the PS4 is $532.
Step-by-step explanation:
The system sells for $399 after giving 25% off on a Black Friday on the sales price.
Let the sales price of the PS4 system is $x.
Then after giving 25% discount the price will become 
Therefore, 0.75x = 399
⇒ x = 532
Therefore, the sales price of the PS4 is $532. (Answer)
The first option and the third option are correct.
(Although, it's probably way too late now...)
if we name that part x, then we can say
1/x = 1/a + 1/b
C represents carrots. t represents time in hours.
c= 125t
To find this equation, I found the unit rate, or how many carrots were chooped per hour. I then plugged it into slope intercept form (y=mx+b) where the y intercept was 0 because she can chop 0 carrots in 0 hours.
