You dived 4,005/16
then you will get your answer
9 divided by 72 = 0.125
0.125 is the weight of one book
0.125 times 80 = 10kg.
So 80 books weight 10kg.
72 divided by 9 = 8 books make up 1 kg.
8 times 6 =48
Length = 20 ft
If he uses 60 ft of fencing to line his rectangular backyard, then the perimeter is 60 ft.
Perimeter formula is ((Width × 2) + (Length × 2))
10 × 2 = 20
20 × 2 = 40
40 + 20 = 60
-4x +12 -12 = -4 -12
-4x = -16
x = 4