What makes composing functions different from doing an arithmetic operation of two functions such as adding or dividing them?

Which of the following shows the length of the third side, in inches, of the triangle below

What is the equation of the line that is parallel to the line with the equation y= -3/4x +1 and passes through the point (12,-12)

James wants to promote his band on the internet. site a offers website hosting for $4.95 per month with a $49.95 startup fee. site b offers website hosting for $9.95 per month with no startup fee. for how many months would james need to keep the website for site a to be a better choice than site b?