Explanation:
what do we need to do ?
just calculate the value of the expression with these values for the variables ?
what's the problem ? this is basic calculating :
-6/2 - 4 + 9×4 = -3 - 4 + 36 = 29
remember (please, for your life !) that multiplication and division always have to be calculated before additions and subtractions (except when brackets force is to go a different route).