Question

factorize : 20-45( m+n)²​

Answer 1

20-45(m+n)

=20(m+n)-45(m+n)

=20m+20n-45m-45n

=20m-45m+20n-45n

= -25m-25n

-25m-25n=0

25(-m-n)=0

-25(m+n)=0

m+n=0

m=0 or n=0