Nina knows that the average of the x-intercepts represents the line of symmetry for a quadratic function through the x-axis. which equation represents the average of the x-intercepts for f(x) = 4x2 – 24x + 20? startfraction negative 5 minus 1 over 2 endfraction = negative 3 = –3 startfraction negative 10 minus 2 over 2 endfraction = negative 4 = –4 startfraction 1 + 5 over 2 endfraction = 3 = 3 startfraction 2 + 10 over 2 endfraction = 4 = 4