Answer:
<em>C) 180 degree rotation </em>
Step-by-step explanation:
While reflecting a point, with coordinates as (x, y), over x axis the new co-ordinates become (x, -y)
⇒(x, y) → (x, -y)
While reflecting a point, with coordinates as (x, y), over y axis the new co-ordinates become (-x, y)
⇒(x, y) → (-x, y)
So, when these two operations are combined, they the rule followed is,
⇒(x, y) → (-x, -y)
We also know that while rotating a point, with coordinates as (x, y), 180° the new co-ordinates become (-x, -y)
⇒(x, y) → (-x, -y)
Therefore, reflecting a point over x axis and then over y axis will yield the same result as rotating a point 180°.
Answer:
When the actual expenses exceed the actual income, the result would be a negative dollar amount. (B)
Step-by-step explanation:
After 6 hours they have descended 6×400 = 2400 feet. The change in elevation is -2400 feet.
So we have the formula:

where

is the distance in kilometers

is the petrol in liters

is the petrol consumption in kilometers per liter
We now for our problem that <span>David drove a distance of 187 km, so </span>

. We also know that he used 28 liters of petrol, so

. Lets replace those values in our formula to find the petrol consumption:



Now, remember that are some rules to determine the number of significant figures in a number:
1. Non-zero digits are always significant figures.
2. A zero between tow significant figures is always a significant figure.
Applying those tow rules we realize that

has 6 significant figures, whereas

has three significant figures and

only two. In mathematical operations with significant figures, the answer should be given with the same significant figures as the number with least significant figures involved in the operations. In our case, that number is

, and

has two significant figures, so our answer should have 2 significant figures. To give our answer with 2 significant figures, we are going to round it:


We can conclude that the patrol consumption of David's vehicle is
6.7 kilometers per liter.