The geometric mean is defined as the nth root of the product of n numbers
1. 4 and 9
Geometric mean = 
2. 5 and 8
Geometric mean = 
3. 8 and 32
Geometric mean = 
4. 64 and 36
Geometric mean = 
Hope that helped!
Q = 7m + 3n
R = 11 - 2m
S = n + 5
T = -m - 3n + 8
simplify Q + S - T
7m + 3n + n + 5 - (-m - 3n + 8) =
7m + 4n + 5 + m + 3n - 8
8m + 7n - 3 <====
Speed = distance/time
So speed = 40/10
= 4m/s