Answer: d = 0
Explanation:
To solve this equation, we will isolate the variable.
7.5d = 2.5d
(7.5d) - 2.5d = (2.5d) - 2.5d
5d = 0
=
d = 0
Elena is correct when she subtracts 2.5d from each side. Since subtraction is the inverse operation of addition, we need to subtract. 7.5d and 2.5 are both like terms, so we subtract the coefficents.