Hello!
I was looking for this answer as well, but I took the quiz and got it correct. The answer is 5 units.
good luck!
Let's the length to be x,
then the width is 8x - 2.
Perimeter of a rectangle = 2*Width + 2*Length
Perimeter of the rectangle = 2(8x-2) + 2x = 16x - 4 + 2x = 18x - 4
Ar the same time, Perimeter of the rectangle = 88.
So, we can write
18x - 4 = 88
18x = 84
9x=42
x= 42/9 cm (length) or ≈ 4.67 cm (length)
8x - 2 = 8*42/9 - 2 ≈ 35.33 cm (width)
Explanation is in the file
tinyurl.com/wpazsebu
-6/7 = -x/84
84/7 = 12
12(-6) = -72
x = -72
So, -6/7 = -72/84 because -72/84 simplifies to -6/7
2(7/2)^x = 49/2
Divide both sides by 2:
(7/2)^x = 49/4
I notice that 49/4 can be rewritten as (7/2)^2, so we now have:
(7/2)^x = (7/2)^2
The only way for this to be true is if x = 2. Thus, we are done.