Question

factorise 20 - 45(m+n)^2
and the answer is
5(2-3m-3n) (2+3m+3n)
please tell me how solve​

Answer 1

Answer:

20-45(m+n)^2

=5{4-9(m+n)^2}

=5{(2)^2-3(m+n)^2}

=5{(2)^2-(3m+3n)^2}

=5(2+3m+3n)(2-3m-3n)