Answer: 
Step-by-step explanation:
Given
Equation is 
Mila uses the first step as multiplication to make the coefficient of x, 1
Mila maybe have multiplied the whole equation by 2 i.e.

C = 16h
This is the basic set up of a cost function which is a direct correlation.
It'd be 9.096491 hope that helps.
You need to win 30 matches in a row to raise its winning percentage to 90%
Letter D
1-sin^2(x) = cos^2(x)
= sin^2(x)/cos^2(x)
= tan^2(x)