Answer:
36 square feet
Step-by-step explanation:
area of the yard: 12×12=144
patio should be 1/4 of the yard, so 144:4=36 is the area of the patio
20 x 10
6 and 7, √ 43 is approximate 6.56
-15
It might help to factor out the expression further. You can factor it as:
(1)(15)(-)
