Question

3(5z + 8) = -21

Explanation:

Step1: Divide both sides by 3

To isolate the term with \( z \), we divide both sides of the equation \( 3(5z + 8)=-21 \) by 3.
\[
\frac{3(5z + 8)}{3}=\frac{-21}{3}
\]
Simplifying both sides, we get \( 5z + 8=-7 \).

Step2: Subtract 8 from both sides

Next, we subtract 8 from both sides to isolate the term with \( z \).
\[
5z + 8 - 8=-7 - 8
\]
Simplifying both sides, we have \( 5z=-15 \).

Step3: Divide both sides by 5

Finally, we divide both sides by 5 to solve for \( z \).
\[
\frac{5z}{5}=\frac{-15}{5}
\]
Simplifying, we find \( z = - 3 \).

Answer:

\( z=-3 \)