Well there is 24 hours in a day so 24 - 15 = 9. So he spends 9 hours awake.
2x-2y
I couldn’t tell if the first figure was a one or a L or i so I solved it as a 1
The average is 2. To find the average you add all the numbers then divide the sum by the total amount of numbers.
Check the picture below
the triangles are similar, the angles are congruents then
so... just add them up, and divide by 2, or set them as rational