I don't get how this works?
The length is 5 units more than the width. The perimeter us 9 times the width.
I'm suppose to find the width and length but I don't think enough info is given.
Perimeter=2[L + W]
The width=W
Length =W + 5
9W =2 [W+5+W]
9W =2W+10+2W
9W - 4W =10
5W =10
W=10 / 5
W = 2 that is the width
2 + 5=7 that is the length, so that:
9 x 2= 2 [2+7]
18 = 18
width = x
length = 5+x
Perimeter = 9x (9 times x)
Draw a rectangle. Mark the widths with x and the lengths with x+5. Now, we know that in order to find perimeter we add all sides. This would be x + x + (5+x) + (5+x) or 2(x) + 2(5+x). We are given the perimeter 9x
To set up this problem, put 2(x) + 2(5+x) equal to 9x
This is 2(x) + 2(5+x) = 9x
To solve, distribute first.
2(x) = 2x
2(5+x) = 10 + 2x
Now you have 2x + 10 + 2x = 9x
Combine like terms
4x + 10 = 9x
And get all the x's on one side
4x + 10 = 9x
-4x -4x
Now you have 10 = 5x
Finally, divide by 5 on both sides.
10/5 = 5x/5
Your answer is 2 = x
To check your answer, go back and fill in every x with two on your rectangle.
2 + 2 + 7 + 7= 18
2 times 9 = 18
Hope this helps!! Sincerly, a pre-calculus student :)
