00:01
In this problem, we're going to go ahead and solve this two -step equation for d, and we'll do this by using two properties, the addition property of equality and the division property of equality.
00:12
These properties basically state that whatever you do to one side of the equation, you have to do to the other to keep the equation true.
00:20
So let's start by solving for 8d.
00:23
We see this minus 15 here.
00:26
To undo the minus 15, we have to do the opposite and add 15.
00:29
We have to do this to both sides because of the addition property of equality to keep the equation true.
00:36
So minus 15 and plus 15 really just kind of cancel each other.
00:39
We have 8d leftover equals a negative 15 plus a 15, which is 0.
00:46
Now, 8 times d, we want to solve for d so we have to undo this multiplication problem.
00:52
So we do the opposite...