55×7/11-55×6/11=? 47/11×1/2-25/11×1/2=?
55 * 7/11 - 55 * 6/11 = 55 * (7/11 - 6/11) = 55 * 1/11 = 55/11 = 5 47/11 * 1/2 - 25/11 * 1/2 = 1/2 * (47/11 - 25/11) = 1/2 * 22/11 = 22/22 = 1