Hello from MrBillDoesMath
Answer: Henry is correct.
Discussion:
Consider this example, m = 3, n = -3. Then
(m+n)^2 = ( 3 -3)^2 = 0^2 = 0 and
m^2 + n^2 = (3)^2 + (-3)^2 = 9 + 9 = 18 which is not equal to 0.
In general (m + n)^2 = m^2 + 2mn + n^2 = m^2 + n^2 + 2mn
Note the highlighted term (2mn) above. That is why Regina's statement fails to be true
Thank you,
Mr. B
