Final answer:
Solving for a variable 'd' such as in d + 3 = 9, we would subtract 3 from both sides to isolate d, which would result in d = 6.
Step-by-step explanation:
With the information provided, if we are to find the value of the variable d in the context of the mixed examples given, we would typically isolate d on one side of the equation.
For example, if we have an equation like d + 3 = 9, we would subtract 3 from both sides to solve for d, resulting in d = 6.
Remember, when subtracting a negative number, you actually add the opposite value.
For example, 2 - (-6) becomes 2 + 6, yielding 8.
This principle follows the rules of addition and subtraction for positive and negative numbers, where similar signs add and yield the same sign and opposite signs subtract, giving the sign of the larger absolute value number.