Perimeter is adding all 4 sides together.
To find the length and width divide total perimeter by 2:
21 / 2 = 10.5
We now know the length of 1 side and the width of 1 side need to equal 10.5.
Since the original piece was a square we also know the width needs to equal 1/2 of the length.
So we have L + 1/2L = 10.5
Add the common terms 1 L + 1/2 L = 1 and 1/2 L
To Find L divide 10.5 by 1-1/2, which equals 7
To find the width subtract 7 from 10.5, which equals 3.5
So the paper is now 3.5 inches by 7 inches.
For this case we have the following factorized expression:

Applying distributive property we have:

We add similar terms taking into account that: Equal signs are added and the same sign is placed.

ANswer:

Rules of exponents come in hand here.
Multiplication rule: a^m x a^n = a^ m+n
Division rule: a^m / a^n = a^m-n
Negative exponent: a^-m = 1/a^m; 1a^-m =a^m
So it would be (-3)^7+5 / (-3)^-2; (-3)^12 / (-3)^-2; (-3)^12 x (-3)^2; (-3)^14
The answer is (-3)^14. If you multiply it out it is 4,782,969.
3/6 6/9 9/12 and so on just keep adding 2/3
The answer is 7.67 by my knowledge