Hey there! I'm happy to help you!
We want to find what d equals, or basically, we want to find d=?
How do we find this?
Well, as you saw, we want to find d equaling something. To do this, we need isolate d on one side of the equation to see what it equals on the other side.
How do we do this, though?
To solve equations, we will use inverse operations. If we had the equation 1+x=2, we have to get the x alone! We have to get rid of the one. To do this, we will subtract 1 from both sides. Why?
Well, if you have a +1 and then you subtract 1, it will equal 0. So we will basically have 0+x=2-1, or x=1!
In our case, we see that d is being divided by -9. To get rid of it, we will multiply both sides of the equation by -9 (division and multiplication are inverse operations!) so that it stays balanced and so we can find our d.
d/-9=-6
d/-9×9=-6/-9 We divide both sides by -9
d=54
You can also plug this value back into the original equation and it will make sense!
54/-9=-6
I hope that this helps you! Have a wonderful day!