Answer:
1) $283.50
2) 65.21 meters.
Step-by-step explanation:
Part 1)
We know that a spool of ribbon holds 6.75 meters.
A craft club buys 21 spools.
So, the total length of ribbon bought is:

Each meter costs $2. So, the total cost will be:

Part 2)
A spool holds 6.75 meters.
We bought 21 of them, so that total length we have is 141.75 meters.
The club used 76.54 meters.
So, the amount of ribbon that is left is represented by:

Subtract:

So, 65.21 meters of ribbon will be left.
To represent the change in points, you can think of it in two ways:
1. You will go down 25 points for every wrong answer, so -25 + -25 + -25 would represent what is happening. They are all negative, so you keeping moving down in value.
2. You can also think of this as 3 groups of -25.
Both answers are -75. The answer is negative because the change was down in points.
-75 is the integer that represents this situation.
For both of these questions you want to raise every part to the 4th or 2nd power. Just remeber that a power raised to a power is just multiplied.
3.)
3^4 = 3×3×3×3 = 9×9 = 81
x^4 = 1×4 = 4 so x^4
2^4 = 2×2×2×2 = 4×4 = 16
so

4.)
2^2 = 2×2 = 4
5^2 = 5×5 = 25
(n^9)^2 = 2×9 = 18 so n^18
so

Hope this helps!
The range of a data set is the difference between the largest and the smallest value in the set.
Here the range is: r = 62 - 25 = 35