It works because 7 x 9 x 10 is the same thing as 7 x 90, since 9 x 10 is just 90. So basically he is just writing more but the answer will still be the same.
Answer:
0.166
Step-by-step explanation:
Answer:
Mark needs 110 ft. fencing to surround all 4 gardens.
Step-by-step explanation:
Mark wants to fence 4 rectangular gardens. So we calculate the perimeter of the each garden by this formula
P = 2(L) + 2(W)
Total Length of the garden = 
= 
Length = 18.5 feet
Total width of the garden = 
= 
Width = 9.0 feet
Perimeter of the garden = 18.5 + 9 = 27.5 feet
Mark wants to fence 4 garden
Therefore, 27.5 × 4 = 110 feet.
Mark needs 110 ft. fencing to surround all 4 gardens.