Let's break down the solution step by step.
Part A:
We want to rewrite the quadratic \(3x^2 + 13x + 12 = 0\) such that we can apply factoring by grouping.
To do this, we first multiply the coefficient of \(x^2\) (which is 3) with the constant term (12):
\[ A \cdot C = 3 \cdot 12 = 36. \]
Next, we need to find two numbers that multiply to 36 and add up to 13.
The pair that works is 9 and 4, because:
\[ 9 + 4 = 13 \quad\text{and}\quad 9 \cdot 4 = 36. \]
Now, we can rewrite the quadratic:
\[ 3x^2 + 9x + 4x + 12 = 0. \]
Now we can group the terms:
- The correct grouping for the equation is:
\[ 3x^2 + 9x + 4x + 12 = 0. \]
Thus, the correct response for Part A is:
3x² + 9x + 4x + 12 = 0
Part B:
After rewriting, we can now factor by grouping:
-
Group the first two terms and the last two terms: \[ (3x^2 + 9x) + (4x + 12) = 0. \]
-
Factor out the common factors in each group:
\[ 3x(x + 3) + 4(x + 3) = 0. \]
-
Now factor out \((x + 3)\):
\[ (3x + 4)(x + 3) = 0. \]
The factored form of the equation is:
(3x + 4)(x + 3) = 0
Part C:
To find the solutions, we set each factor equal to zero:
-
From \(3x + 4 = 0\): \[ 3x = -4 \quad \Rightarrow \quad x = -\frac{4}{3}. \]
-
From \(x + 3 = 0\): \[ x = -3. \]
Thus, the solutions are:
x = -4/3 and x = -3.
The correct answer for Part C is:
x = -4/3 and x = -3.