X = number of cds on the rack
x + 7 = 30
x = 30 - 7
x = 23 <== so there are currently 23 cds on the rack
Answer:
5 hours
Step-by-step explanation:
Time taken for trip : t + 1
Time taken for return : t
Avg. speed (trip) : 256 km/h
Avg. speed (return) : 320 km/h
The distances covered on both trips are equal.
⇒ Distance (trip) = Distance (return)
⇒ Speed (trip) × time (trip) = Speed (return) × time (return)
⇒ (256)(t + 1) = (320)(t)
⇒ 256t + 256 = 320t
⇒ 64t = 256
⇒ t = 4 hours
<u>Time (trip)</u> = t + 1 = 4 + 1 = 5 hours
The answer to 9+10 is 19 because if you add 9 to the number 10, you get 19