(9m^2+5mn-4n^2(-(7m^2+3mn+6n^2)

Equations equal to this one

One equation equal to the given expression is:

-9m^2 + 5mn + 4n^2 = 7m^2 + 3mn + 6n^2

Another one

Another equation equal to the given expression is:

18m^2 - 10mn - 8n^2 = -14m^2 - 6mn - 12n^2

Another one, maybe using 16mn?

Sure! Here's another equation equal to the given expression using 16mn:

-9m^2 + 5mn + 4n^2 = -7m^2 - 3mn - 6n^2 + 16mn

What about 2m^2

Certainly! Here's another equation using 2m^2:

9m^2 + 5mn - 4n^2 = 2m^2 - (7m^2 + 3mn + 6n^2)