Л) -2 2/5 - (-3 3/8-2 1/4) М) -3,15-(-4 1/2 + 3 3/4)

Л) -2 2/5 - (-3 3/8 - 2 1/4) = -(2 * 5 + 2)/5 + (3 * 8 + 3)/8 + (2 * 4 + 1)/4 = -12/5 + 27/8 + 9/4 = -12 * 8/40 + 27 * 5/40 + 9 * 10/40 = -96/40 + 135/40 + 90/40 = (135 - 96 + 90)/40 = 129/40;

М) -315/100 - (-4 1/2 + 3 3/4) = -63/20 + (4 * 2 + 1)/2 - (3 * 4 + 3)/4 = -63/20 + 9/2 - 15/4 = -63/20 + 90/20 - 75/20 = (90 - 63 - 75)/20 = -48/20 = -12/5.