The following expressions form a series followed by a

Solution

Given, x² - 6x - 720 = 0 Or, x² - 30x + 24x - 720 = 0 Or, x(x - 30) + 24(x - 30) = 0 Or, (x - 30)(x + 24) = 0 So, x = 30 or x = -24 So, x = 30 So, (x - 10) = 20 (x + 10) = 40 (x - 10) × x = 20 × 30 = 600 (1540 × x) = 1540 × 30 = 46200 So, the series becomes: 20, 40, 120, 600, 4500, 46200, ? The series follows the pattern as: 20 × 2 = 40 40 × 3 = 120 120 × 5 = 600 600 × 7 = 4200 4200 × 11 = 46200 So, 4200 should come in place of 4500. And, ? = 46200 × 13 = 600600 Or, 600600 ÷ 30 = (20020 × x)