若是 x^2+49+(15+x)^2+49 = 2252x^2 + 30x + 98 = 0x^2 + 15x + 49 = 0x = [-15 ± √(15^2-4· 49)]/2 = (-15 ± √29)/2 若是 x^2+49+(15-x)^2+49 = 2252x^2 - 30x + 98 = 0x^2 - 15x + 49 = 0x = [15 ± √(15^2-4· 49)]/2 = (15 ± √29)/2