Explanation:
The square mural in Olivia's classroom has dimensions x by x.
Then she paints a mural of dimensions: x+5 (the length) by x-2 (the width).
Thus the second mural (the hallway mural) has the shape of a rectangle with dimensions (x+5) by (x-2), so the area of the second mural is
(x+5)(x-2).
each side of the classroom mural is 7 feet means that x = 7 ft,
thus the area of the hallway mural is :
(x+5)(x-2)=(7+5)(7-2)=12*5=60 (square feet)
So the answer is 60 square feet.