Answer:
To check whether 40, -40, 16, or -16 is the solution of the equation 28 = d - 12, we can substitute each value into the equation and see if it results in a true statement.
When we substitute 40 into the equation, we get:
28 = 40 - 12
Simplifying, we get:
28 = 28
This is a true statement, so 40 is a solution of the equation.
When we substitute -40 into the equation, we get:
28 = -40 - 12
Simplifying, we get:
28 = -52
This is not a true statement, so -40 is not a solution of the equation.
When we substitute 16 into the equation, we get:
28 = 16 - 12
Simplifying, we get:
28 = 4
This is not a true statement, so 16 is not a solution of the equation.
When we substitute -16 into the equation, we get:
28 = -16 - 12
Simplifying, we get:
28 = -28
This is not a true statement, so -16 is not a solution of the equation.
Therefore, the only solution of the equation 28 = d - 12 is d = 40.