How do i solve 86.5 square - 13.5 square ?
The difference of two squares property is shown below.
a^2 – b^2 = (a – b)(a + b)
you can verify that the above relation is true by simply multiplying out the rhs.
a^2 – b^2 = a^2 + ab – ba – b^2
a^2 – b^2 = a^2 – b^2
Applying this property to your own problem,
86.5^2 – 13.5^2 = (86.5 – 13.5)(86.5 + 13.5)
86.5^2 – 13.5^2 = 73 * 100
86.5^2 – 13.5^2 = 7300
Answer = 7,300