resolva as expressões a)3/5+1/2
b)-4/9+2/3 c) -1/3-1/3 d) 1/2-1/3+1/5 e)2-[2/5-(1/2+1/4) f)2/10+(2/3-1/4)-(-7/13+4/3) g) 2,5-[3,2+(2,6_4,3)+0,5] h)2,8-3,6+4,2-2,4 i)5,72-3,26+2,31-2,53​