Answer:
9x^2 - 36x + 36 sq. ft. (the first option).
Step-by-step explanation:
Area of a square of side d = d^2.
So area of this square = (3x - 6)^2
= (3x - 6)(3x - 6)
= 3x(3x - 6) - 6(3x - 6)
= 9x^2 - 18x - 18x + 36
= 9x^2 - 36x + 36 sq ft.
Given that the distance between two lines in the measurement instrument is 0.01m, the maximum error should be 0.01m/2 = 0.005 m.
If you do a good work, the real measure is 1.20m +/- 0.005m, this is between 1.195 and 1.205.
U write it as 1/6+1/6+1/6+1/6=4/6