Question: User: $-3x^2 + 15x + 108$
1. **State the problem:**
We need to factor the quadratic expression $$-3x^2 + 15x + 108$$.
2. **Formula and rules:**
To factor a quadratic expression of the form $$ax^2 + bx + c$$, we look for two numbers that multiply to $$a \times c$$ and add to $$b$$.
3. **Step 1: Factor out the greatest common factor (GCF):**
The GCF of $$-3x^2$$, $$15x$$, and $$108$$ is $$-3$$.
$$-3x^2 + 15x + 108 = -3(x^2 - 5x - 36)$$
4. **Step 2: Factor the quadratic inside the parentheses:**
We want two numbers that multiply to $$-36$$ and add to $$-5$$.
These numbers are $$-9$$ and $$4$$ because $$-9 \times 4 = -36$$ and $$-9 + 4 = -5$$.
5. **Step 3: Write the factored form:**
$$-3(x - 9)(x + 4)$$
6. **Final answer:**
The factored form of $$-3x^2 + 15x + 108$$ is $$-3(x - 9)(x + 4)$$.