
To solve for d:
1. Remove parenthesis:

2. Leave the terms with d in one side of the equation:
-Add 1.2 in both sides of the equation:

-Substract 0.3d and 0.1d in both sides of the equation:

3. Opperate similar terms:

4. Divide into (-0.2) both sides of the equation:

Then, d is -16