Combine the like terms to create an equivalent expression:

{-3z-z}−3z−z

{-3z-z}−3z−z = -4z -3z - z = -8z.

To combine like terms, we need to add or subtract the coefficients of the similar terms. In this case, the similar terms are -3z and -z.

{-3z - z} - 3z - z

Combining the coefficients of -3z and -z, we get -3 - 1, which is -4.

So the equivalent expression is:

-4z - 3z - z

Simplifying further:

-7z - z

The final equivalent expression is:

-8z

To combine like terms, we need to add or subtract the coefficients of the same variable. In this case, we have two variables, z and -z.

First, let's combine the z terms. We have -3z - z. To add these, we add their coefficients:

-3z - z = -3z - 1z = -4z.

Now, let's combine the -z terms. We have -3z - z and -3z - z. Again, we add their coefficients:

-3z - z = -3z - 1z = -4z.

Finally, the expression becomes:

-4z - 3z - z.

Combining like terms, we get:

-4z - 3z - z = -8z.