вычислите 3/5+2/15, 5/12(1/12+1/4),1/25+3/20+4/25+1/20,3/5+5/6-7/30

1.) 3/5+2/15=11/52.) 5/12(1/12+1/4)=5/12(1/3)=5/363.) 1/25+3/20+4/25+1/20=5/25+4/20=1/5+1/5=2/54.)3/5+5/6-7/30=18+25-7/30=6/5