Question

what are the solutions to this quadratic?
\\y = 9x^2 - 49\\
\\x = \pm \frac{7}{3}\\
\\x = \pm \frac{3}{7}\\

Explanation:

Set the quadratic function to zero

Using the Solving Quadratic Equations knowledge point

$$ 9x^2 - 49 = 0 $$

Isolate the variable term

Using the Solving Quadratic Equations knowledge point

$$ 9x^2 = 49 $$

Divide by the coefficient

Using the Solving Quadratic Equations knowledge point

$$ x^2 = \frac{49}{9} $$

Apply the square root property

Using the Square Root Property knowledge point

$$ x = \pm\sqrt{\frac{49}{9}} = \pm\frac{7}{3} $$

Answer:

• (A) \(x = \pm\frac{7}{3}\) (Correct answer)
• (B) \(x = \pm\frac{3}{7}\)