To solve the equation \(-3(y + 6) = 21\), the first step would typically be to eliminate the coefficient of \(-3\) in front of the parentheses. The second step follows after that and involves simplifying the equation after the first operation has been performed.
The correct first step is to divide both sides by \(-3\):
\[ y + 6 = -7 \]
After this, the second step would be to subtract \(6\) from both sides:
\[ y = -7 - 6 \] \[ y = -13 \]
So, the second step in solving the equation is:
Subtract 6 from both sides.