[(6m² + 3m - 6 )-(4m³ - 5m +9 )]-(m² + m)

-4m^3+5m^2+7m-15

Step-by-step explanation:

To evaluate this, we open the brackets and collect like terms.

[(6m^2 + 3m -6)] - (4m^3 -5m +9)- (m^2+m)]

Opening the brackets(note; we multiply the elements in each of the brackets by the sign in front of the bracket) we have;

6m^2+3m-6 -4m^3+5m-9 -m^2-m

We collect like terms;

-4m^3+6m^2-m^2+3m+5m-m-6-9

-4m^3+5m^2+7m-15

Kindly note 6m^2 is same as 6 raised to the power of 2