Answer:
d = 5
Explanation:
So I am assuming you are solving for the variable d. The first step you would want to take is combining all the like terms, in this case, all of the d's. In simpler terms, ignore the d's at first and we simply are doing:
3 minus 18 minus negative 13.
3 minus 18 is negative 15, then subtracting a negative number is the same as adding a positive number. In this case we add 13 to negative 18 and get negative 2. Now we can add the variable back in'
-2d = -10
Now since both of these numbers are negative we can simply multiply both sides by -1, making the entire equation positive.
2d = 10
Now in order to get the d by itself we must perform the opposite equation to move the 2 onto the other side with the 10.
2d is simply 2 times the value of d, so we need to divide the number, on both sides which would be 10/2 which has this equaling
d = 5