Mathieu is finding the x-intercepts of the function

f (x) = x2 + 4x + 3. His work is shown below.

Which error did Mathieu make?

He factored incorrectly.

He did not use the constant as the x-intercept.

O He set the factored expressions equal to each

other.

1.0 = x2 + 4x + 3

2. 0 = (x + 3) (x + 1)

3. x + 3 = x + 1

4. X = X-2

5.0 = - 2

6. There are no x-intercepts.

O He incorrectly solved the equation x + 3 = x + 1.