9a-17a-30a+4a

To simplify the expression, you simply need to combine all the like terms (terms containing the variable 'a' in this case). Here's how you do it:

9a - 17a - 30a + 4a

Combine the 'a' terms by adding or subtracting their coefficients:

(9 - 17 - 30 + 4)a Now, perform the arithmetic with the coefficients:

9 - 17 = -8 -8 - 30 = -38 -38 + 4 = -34

So when you combine it all, it becomes:

-34a

The simplified expression is -34a.