... shown above). The real number line is infinitely long in both directions. For any two numbers on the real number line, the number to the left is less than the number to the right. For example, ... equation can always be solved by the formula: xbb aca=- -242. For example, in the quadratic equation 2602xx =, a = 2 , b=-1, and c=-6. Therefore, the formula yields x = ()-()-()-()()==114262214941742 ... units above the x-axis, it is identified by the ordered pair (4, 1.5). The origin O has coordinates (0, 0). Unless otherwise noted, the units used on the x-axis and the y-axis are the same....