The answer to your question is 6.28mi
Percent error : (approximate value - exact value) / exact value.....x 100
percent error : (5.75 - 6.25) / 6.25......ignore any negative signs
0.5 / 6.25 = 0.08.....x 100 = 8% error <==
14.
4(5.6) = 4(6.0 - 0.4) = 4(6.0) - 4(0.4) = 22.4
16.
4(6 + 7) = 4(6) + 4(7) = 52
18.
14(10 - 5) = 14(10) - 14(5) = 70
Easy peasy, this is a representation of differnce of 2 perfect squares
a^2-b^2=(a-b)(a+b)