Let n = length
let n-4 = width since it is 4 meters shorter
2( n+n-4) =72 Two of the length and width added together equal the perimeter
combine like terms
2(2n -4) = 72 Now use the distributive law on the left side of the equation
4n -8 = 72 Now add 8 to both sides
4n -8 +8 = 72 +8
4n = 80 Finally divide each side by 4
n=20
so the length is 20 and the width is 4 less or 16.
Let's see if our answer works.
20 + 16 + 20 +16 =? 72
72 =72 yes, it does. Length = 20 Width = 16
First find the factors of 20
1 & 20
2 & 10
4 & 5
-1 & -20
-2 & -10
-4 & -5
Now find the pairs that have a difference of 1
-4 & -5
4 & 5
Well, if 'y' has zeros at x=6 and x=-8,
then 'y' must be the product
y = (x - 6) (x + 8)
Perform the multiplication to get the quadratic function:
y = x² + 2x - 48
6:14 + 2 hours = 8:14
8:14 + 20 minutes = 8:34
8:34 + 8 minutes = 8:42
C
