<em>Look</em><em> </em><em>at</em><em> </em><em>the</em><em> </em><em>attached</em><em> </em><em>picture</em>
<em>Hope </em><em>it</em><em> </em><em>will</em><em> </em><em>help</em><em> </em><em>you</em>
<em>Good</em><em> </em><em>luck</em><em> </em><em>on</em><em> </em><em>your</em><em> </em><em>assignment</em>
Hi there! :)

Find the perimeter by solving for y.
We know that a rectangle contains two pairs of parallel and congruent sides, therefore:
5y - 1 = 2y + 8
We can solve for y using this expression. Begin by subtracting 2y from both sides:
5y - 2y - 1 = 2y - 2y + 8
3y - 1 = 8
Add 1 to both sides:
3y - 1 + 1 = 8 + 1
3y = 9
Divide both sides by 3:
y = 3
Recall that the perimeter of a rectangle is:
P = 2l + 2w
Plug in the given expressions for the side lengths to find one equation:
P = 2(5y - 1) + 2(y - 1)
Simplify by distribution:
P = 10y - 2 + 2y - 2
Combine like terms:
P = 12y - 4
Plug in the solved value of y into this equation:
P = 12(3) - 4
P = 36 - 4
P = 32 cm.
Nine.....................
Simply put, it says that the numbers can be added in any order, and you will still get the same answer. For example, if you are adding one and two together, thecommutative property<span> of addition says that you will get the same answer whether you are adding 1 + 2 or 2 + 1. This also works for more than two numbers.</span>