When you start out solving this, you don't know what the number is, but you still need a name to call it. You can use any name you want when you do it, like 'x', 'y', 'z', 'Q', or 'Stewy'.
Right now, the one solving it is me, so I can use any name I like. I like "Ralph". Until I figure out what the unknown number really is, I'm calling it 'Ralph'.
The quotient of the number and 3 . . . . . (Ralph / 3)
The negative of 8 . . . . . -8
But the question says that these are equal, so you can write
Ralph/3 = -8 . <== This is the equation that the question is asking for.
How to solve it, and find out what number Ralph really is:
Take the equation . . . . . Ralph/3 = -8
Multiply each side by 3: (Ralph/3) x 3 = (-8) x 3
Simplify that . . . . . Ralph = -24