Mathieu is finding the x-intercepts of the function f(x) = x2 4x 3. His work is shown below. 0 = x2 4x 3 0 = (x 3)(x 1) x 3 = x 1 x = x – 2 0 = –2 There are no x-intercepts. Which error did Mathieu make? He factored incorrectly. He did not use the constant as the x-intercept. He set the factored expressions equal to each other. He incorrectly solved the equation x 3 = x 1.