3/7 + (-5/2) + (-3/5)

a, 3/7+(-5/2)+(-3/5)

b, -8/18-15/27

c, 4/5-(-2/7)-7/10

d, 3,5-(-2/7)

e, -6/21.3/2

f, (-3).(-7/12)

j, (11/12:33/16).3/5