What is the null hypothesis H0 out of 45% and 75%

Shryia read a 481 -page-long book cover to cover in a single session, at a constant rate. after reading for 1.5 hours, she had 403 pages left to read. how fast was shryia reading? pages per hour how long did it take her to read the entire book? hours plz i realy need this

A. 90 degrees b. 45 degrees c. 30 degrees d. 120 degrees

Asystem of equations has 1 solution. if 4x-y=5 is one of the equations , which could be the other equation ?