Answer:

Step-by-step explanation:
In order to make d the subject of the formula, you need to isolate it. 
- You started with d-7 = 4d + 3/e
- Move 4d to the left side by subtracting 4d from both sides to cancel it from the right so you have...
d - 7 = 4d + 3/e              This will leave you left with -3d - 7 = 3/e
-4d     -4d                           
- Then move over the -7 by adding 7 to both sides...
-3d - 7 = 3/e              This will leave you left with -3d = 3/e + 7
      +7          +7
- Finally to get d by itself divide both sides of the equation by -3 and you'll be left with...
 
- You can cancel out the 3 in the -3/3e and make it -1/e so your final answer will be 
