Answer:
I think its c but I'm not sure. You need to ask a professional.
Step-by-step explanation:
The change is given by the difference between how much you paid and how much you actually had to pay. For example, if you pay with a $50 bill and you had to pay $13, your change will be
dollars.
In this case, we have

So, Gabriel's mistake was to leave the negative sign to the "-2" at the end of the expression, instead of flipping it to positive "+2" when subtracting it.
Answer:
2, 19, -3
Step-by-step explanation:
Repetition is a guaranteed way to learn something. If it is a formula you need to learn, try doing flashcards and reading it over and over again until you can spell it without the flahcard. If it is something like factoring, just do a bunch of factoring problems until you get the feel of it.
Answer:
C. 
Step-by-step explanation:
We proceed to solve for
by the Pythagorean Theorem:
(1)





There are two different solutions:
, 
A solution of
is considered realistic when the length of every side of the triangle is a not negative number.














The only realistic set of solutions is for
, and the radius of the circle is represented by the line segment
: 
And the area of the circle (
) is calculated from the following formula:



The correct answer is C.