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.