Step-by-step explanation:
The line above the letter means "complement". If X is a set, the the complement of X (denoted by X with a line above it) is the set of all things not in X...If X is a set, then the complement of X (denoted by X with a line above it) is the set of all things not in X.
Sorry if it was complicated
Length: 2w-12
Area is length times width so (2w-12)*w
Or 2w^w-12w
The top and bottom faces are 3 inches by 3 inches.
Area = 3 in. * 3 in. * 2 = 18 in.^2
The front, back, right, and left faces are 3 in. by 6 in.
Area = 3 in. * 6 in. * 4 = 72 in.^2
Total surface area = 18 in.^2 + 72 in.^2 = 90 in.^2
Answer: B. 90 square inches
8 + 2(10 - r) = 8 + 20 - 2r = 28 - 2r
