9. \( \frac{d}{9}=-2 \)

To solve the equation \( \frac{d}{9} = -2 \), you need to isolate \( d \). You can do this by multiplying both sides by 9. This gives you \( d = -2 \times 9 \), so \( d = -18 \). And just like that, you've found your solution! Always remember, when isolating a variable, whatever operation you perform on one side of the equation you must also perform on the other side. Simple, right? This keeps the balance of your equation intact!