Here is your equation:
In this equation, you're looking for the value of d alone. That means you would have to move everything next to the variable to the other side. You can do that by doing the opposite of what's being done to it.
In this equation, 5d is being subtracted by 10(-10). The opposite of that is adding 10(+10). You would have to add 10 to both sides, since -10 and +10 cancel out each other.
The first thing you are going to do is add 10 to both sides.
Now you're left with the equation <em>5d=30. </em>Remember that you're looking for d alone. In the current equation, d is being multiplied by 5(5d ⇒ 5 × d). Again, you're going to do the opposite of what's being done to it. The opposite of multiplying is dividing, therefore, you're going to divide both sides by 5, since the 5 divided by 5 is 1, which cancels out the 5.
Divide both sides by 5.
That means the answer to your equation is d = 6.