Combine like terms and eliminate parenthesis.5z-[2z-(13z+8)]

We need to start from the innermost parenthesis and work our way out.

The first parenthesis is . These are not like terms because one involves a variable, while the other is a constant term. Two terms are summable if they involve the same power(s) of the same variable(s).

So, we can take one step outwards, and we arrive to the square brackets. We have

and 2z and -13z are like terms, so we can sum them:

Finally we arrive to the whole expression, which is

Because, again, 5z and 11z were like terms.

answer: they are supplementary angles

step-by-step explanation: 161+19=180. supplementary angles equal 180 degrees