Answer:
It's linear
Step-by-step explanation:
Linear equations have no exponents higher than a 1, which is the case for this equation cause if there's no exponent it's cause it's just a 1. Non-linear has a exponent higher than a 1, ex. 
Umm i would not trust that file
Answer:
Let x = the number
2(x-5) = 9
2x - 10 = 9
2x = 19
x = 9.5
Step-by-step explanation:
T = 0
=> Q = 0
t = x
=> Q = arcsin(x/a)
rest it just simple integration of trigonometric function