Lisa solved 3x2 + 1 = 28 as shown.
3x2 + 1 = 28
3x2 = 27
x2 = 9
She concluded that the solutions to this quadratic equation are x = -9 or x = 9. Using a complete sentence, explain what mistake she made.
also
Lisa solved 3x2 + 1 = 28 as shown.
3x2 + 1 = 28
3x2 = 27
x2 = 9
She concluded that the solutions to this quadratic equation are x = -9 or x = 9. What are the correct solutions to this quadratic and how did you arrive at your answer?
