Which expression is equivalent to (9m^2 + 5mn - 4n^2) - (7m^2 + 3mn + 6n^2)
To find the equivalent expression, we need to subtract the second expression from the first.
(9m^2 + 5mn - 4n^2) - (7m^2 + 3mn + 6n^2)
= 9m^2 + 5mn - 4n^2 - 7m^2 - 3mn - 6n^2
= (9m^2 - 7m^2) + (5mn - 3mn) + (-4n^2 - 6n^2)
= 2m^2 + 2mn - 10n^2
Therefore, the expression (9m^2 + 5mn - 4n^2) - (7m^2 + 3mn + 6n^2) is equivalent to 2m^2 + 2mn - 10n^2.