-30+20:[-5]

To solve the expression \(-30 + 20 : [-5]\), we first need to clarify the operations. It looks like you are using ":" to denote division. So, this translates to:

\[ -30 + \frac{20}{-5} \]

Next, we will perform the division:

\[ \frac{20}{-5} = -4 \]

Now we substitute this back into the expression:

\[ -30 + (-4) \]

This simplifies to:

\[ -30 - 4 = -34 \]

Therefore, the final answer is:

\[ \boxed{-34} \]