its definitely -2.5........
Let's call the stamps A, B, and C. They can each be used only once. I assume all 3 must be used in each possible arrangement.
There are two ways to solve this. We can list each possible arrangement of stamps, or we can plug in the numbers to a formula.
Let's find all possible arrangements first. We can easily start spouting out possible arrangements of the 3 stamps, but to make sure we find them all, let's go in alphabetical order. First, let's look at the arrangements that start with A:
ABC
ACB
There are no other ways to arrange 3 stamps with the first stamp being A. Let's look at the ways to arrange them starting with B:
BAC
BCA
Try finding the arrangements that start with C:
C_ _
C_ _
Or we can try a little formula; y×(y-1)×(y-2)×(y-3)...until the (y-x) = 1 where y=the number of items.
In this case there are 3 stamps, so y=3, and the formula looks like this: 3×(3-1)×(3-2).
Confused? Let me explain why it works.
There are 3 possibilities for the first stamp: A, B, or C.
There are 2 possibilities for the second space: The two stamps that are not in the first space.
There is 1 possibility for the third space: the stamp not used in the first or second space.
So the number of possibilities, in this case, is 3×2×1.
We can see that the number of ways that 3 stamps can be attached is the same regardless of method used.
First two are the explanation and the last one is the answer :)
Answer:

Step-by-step explanation:
Slope intercept form is a way of modeling a quadratic equation, where the coefficient of the term (
) is the slope (change) of the line, and the constant is the y-intercept. In essence;(
), where (
) is the slope and (
) is the y-intercept.
The slope of the given line is (
) because, this is the rate at which the candle burns, therefore, it is the change in the line. The change is (
) because this is the rate of burning, the slope is also negative since the height is decreasing. (
) is the y-intercept because it is the starting height of the candle. One will take the time since the start of burning the candle, multiply it by the slope, and add it to the y-intercept to find the current height of the candle. Therefore, the equation is (
), where the output (
) is the current height of the candle, and the input (
) is the time at which the measruement was taken.
All the correct answers are C and D.