lg (31.47 * 10^10) = lg (47.21 * 10^10) - c/450 + c/550
lg (31.47 * 10^10) - lg (47.21 * 10^10) = c/550 - c/450
lg (31.47 * 10^10 / 47.21 * 10^10) = (450c - 550c)/450*550
lg (31.47 / 47.21 ) = - 100c / 24750
lg (31.47 / 47.21 ) = - c / 2475
c = - 2475 * lg (31.47 / 47.21 )
