To solve the quadratic equation \( 84x^2 + 16x = 0 \) by factoring out the greatest common factor (GCF), we first identify the GCF of the terms:
- \( 84x^2 \)
- \( 16x \)
The GCF of \( 84 \) and \( 16 \) is \( 4 \), and both terms also contain \( x \). Thus, the GCF is \( 4x \).
Now, we can factor out \( 4x \) from the equation:
\[ 84x^2 + 16x = 4x(21x + 4) = 0 \]
Next, we set each factor equal to zero:
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From \( 4x = 0 \): \[ x = 0 \]
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From \( 21x + 4 = 0 \): \[ 21x = -4 \quad \Rightarrow \quad x = -\frac{4}{21} \]
Thus, the solutions to the equation \( 84x^2 + 16x = 0 \) are:
\[ x = 0 \quad \text{and} \quad x = -\frac{4}{21} \]
The correct response is:
The solutions are \( x = 0 \) and \( x = -\frac{4}{21} \).