Question

M^4 - 3m^3 n + m^2n^2 - m^3n - 4mn^3 ghb m= -1 n= 1

Answer 1

$m^{4}-4 m^{3}n-4m n^{3}+ m^{2} n^{2} = m^{2}( m^{2} + n^{2} )-4mn( m^{2} + n^{2} ) = = ( m^{2}+ n^{2})( m^{2}-4mn) = m( m^{2} + n^{2})(m-4n) -1(( -1)^{2}+ 1^{2})(-1-4*1) = 10$