Example: Given that m-2n = 3 and Mn = 2, find the square of (1)(m+2n)(2)m-the square of Mn+4n.
Because m-2n = 3 and Mn = 2, the square of (m-2n) = the square of m-the square of -4mn+4n = the square of m-the square of 8+4n =9.
So the square of m+the square of 4n = 17.
Square of (1) (m+2n) = square of m+square of +4mn+4n =25.
(2) the square of m-the square of Mn+4n = 15.