Answer:
The answer is d. 25
Step-by-step explanation:
a=-3,b=-7,c=-15
|a+b|+|c|
=|-3-7|+|-15|
=|-10|+|-15|
=10+15
=25
Y=400-10d
If he reads 10 pages a day and there is 400 total pages then you plug in an amount of days (d) to find the total amount of days it takes him to read the book.
9.6 months that is how long the investment lasted.