The area of the scale drawing would be 1080 square centimeters or (1080 cm^2). I got this answer through first finding the area of the classroom in feet (which is A= lw = [18][20] = 360 ft^2) and then I proceeded to converting it to centimeters via given scale factor (3 cm = 1 foot) and had the answer of 1080 centimeters squared.
The answer is B since a negative number being subtracted cancels out and becomes a number, for example: since its -(-3) it becomes positive.
The answer would be 6b-3c because a would cancel out and be 0
