-1 2/5+(-3 4/5)= -7/5 - 19/5 = -26/5 = 5 1/5
-3/4+(-2/3) = -3/4 -2/3 = -9/12 -8/12=-17/12 = - 1 5/12
-7/15+(-3/40) = -7/15 - 3/40 = -56/120 - 9/120 = -65/120 = -13/24 = - 1 11/13
-3 11/20+(-2 19/30) = -71/20 - 79/30 = - 213/60 - 158/60 = - 371/60 = 6 11/60