The word decreased indicates that a negative internet should be used
For this case we have the following equation:

Let 
We have:

By definition, given an equation of the form 
The quadratic formula, to find the solution can be written as:

In this case we have:

Substituting in the quadratic formula we have:
See attached image
Answer:
Option B
You cross the date line into Monday.
_____
The next day after Monday is Tuesday. (I find it difficult to tell the intent of the question.)
Answer:
450
Step-by-step explanation:
Multiply the length (30) by the width (15)
30x15=450