Step-by-step explanation: From the start of the equation, we know it must factor to something like (3m + x)(n+y), because the first term must be 3mn. Now, for the next term to be -6n, y must be -2, and for the third term to be 5n, x must be positive 5. So we end up with (3m+5)(n-2). If we factor this out, we get 3mn-6m+5n-10, meaning the final term is -10.
