Answer:
width= 27 ft, length=78 ft
Step-by-step explanation:
P=2l+2w
210=2l+2w
Divide by 2
105=l+w
l=5w-57
Substitute for l
105=6w-57
6w=162
w=27
l=5(27)-57
=135-27
l=78
The commutative property of addition can be used to rarrange this to
... 0 + 18 + 34 + 26
Then the identity property of addition can be used to remove the 0 term
... 18 + 34 + 26
We can use the associative property of addition to form the sum of 34 and 26, convenient because 4 and 6 "make a 10". That sum is 60, so now the sum is
... 18 + 60
which is easily seen to be
... 78
