122 divided by 3.14 is 38.9.
38.9 divided by 13 is 2.9 = 3 hours
AC = AB + BC
AB=5x-19,and BC= 3x+4 given;
So
AC = 5x-19 + 3x+4
Simplify
AC = 8x -15
Answer:
The unit price of the book is 0.75.