To solve the inequality \(-3|x+1| \geq -12\), we can first divide both sides by \(-3\). Remember that dividing by a negative number flips the inequality sign.
\[ |x+1| \leq 4 \]
The absolute value inequality \(|x+1| \leq 4\) means that the expression inside the absolute value, \(x + 1\), must lie within the interval \([-4, 4]\). We can express this as two separate inequalities:
\[ -4 \leq x + 1 \leq 4 \]
Now, we can solve for \(x\):
- From \(-4 \leq x + 1\):
\[ -4 - 1 \leq x \implies -5 \leq x \]
- From \(x + 1 \leq 4\):
\[ x \leq 4 - 1 \implies x \leq 3 \]
Now we have:
\[ -5 \leq x \leq 3 \]
In interval notation, this is written as:
\[ [-5, 3] \]
Thus, the solution to the inequality \(-3|x+1| \geq -12\) is:
\[ \boxed{[-5, 3]} \]