a) -3,5+(-4 1/2)-6,25+(-5)-(-7,1) = -3,5-4,5-6,25-5+7,1 = -12,15
b) -6 1/4-(-5,5)+(-4,7)-(-1 9/20)+(-3 3/10) = -6,25-5,5-4,7+1,45-3,3 = -18,3
c) 2 3/8+(-1 2/3-2 5/6)-3 1/12 = 2 9/24- 1 16/24-2 20/24-3 2/24 = 57/24-40/24-68/24-74/24 = -125/24 = -5 5/24
d) 7 5/7-(12-19,4)+(-18) = 7 5/7+7,4-18 = 7 5/7-10 6/10 = 7 50/70 - 10 42/70 = 495/70 - 742/70 = -247/70 = -3 37/70
e) (-5,125-3 1/5)-(7,5-4 3/4)+(-2 1/2) = (-5,125-3,2)-(7,5-4,75)-2,5 = -8,325-2,75-2,5 = -13,575