Answer:
-15x+24
Step-by-step explanation:
You can write that as:

Both sides aren't equal because 1-sin^2x = cos^2x and cos^2x / 1+cosx can never equal cosx
2y+7z hope this helped dude
Answer:
- 16
Step-by-step explanation:
Average is calculated as
average = 
Thus for the given 10 numbers we have
= - 5 ( multiply both sides by 10 )
total = - 50
let the number added be x, then
= - 6 ( multiply both sides by 11 )
total + x = - 66, that is
- 50 + x = - 66 ( add 50 to both sides )
x = - 16
The new number is - 16