[tex] = (11 {m}^{2} {n}^{2} + 2mn - 11) - (5 {m}^{2} {n}^{2} - 6mn + 17)[/tex]
[tex] = 11 {m}^{2} {n}^{2} + 2mn - 11 - 5 {m}^{2} {n}^{2} + 6mn - 17[/tex]
[tex] = (11 {m}^{2} {n}^{2} - 5 {{m}^{2} } {n}^{2} ) + (2mn + 6mn) + ( - 11 - 17)[/tex]
[tex] = 6 {m}^{2} {n}^{2} + 8mn - 28[/tex]
The other person is wrong
I can say that for sure.
