вычислите(1/3+0,5)*2 2/5-(1/2-0,3)*3,5

=(1/3+5/10)*12/5-(1/2-3/10)*7/2=
=(10/30+15/30)*12/5-(5/10-3/10)*7/2=
=25/30*12/5-2/10*7/2=
=5/6*12/5-1/5*7/2=
=2-7/10=
=20/10-7/10=
=13/10=
=1 3/10