1.3 7/15+1,4=52/15+14/10=104+42/30=146/30=4 26/30.
2 7/9+6,9=25/9+69/10=250+621/90=871/90=9 61/90.2 5/6-1,4=17/6-14/10=85-42/30=43/30=1 13/30.
57/24-2,75=127/24-275/100=12700-6600/2400=6100/2400=2 1300/2400.
19,375-(12 7/9-8,25)=19,375-(115/9-825/100)=19,375-(11500-7425/900)=19,375-4075/900=19,375-81/18=19,375-4,5=14,875.
4,75+1 1/3-1 3/4=475/100+4/3-7/3=1425+400-700/300=1125/300=3,75.
4,53+5 5/11+2,47=453/100+60/11+247/100=4983+6000+2717/1100=13700/1100=12 500/1100.
3,8+2 2/7-3 4/5=38/10+16/7-19/5=1330+800-1330/350=800/350=2 100/350
2б.
1.3,125+1,105=4,23
2.0,6+0,6=1,2
3.7,12-4,12=3
4.4,26-2,026=2,234
5.2,015-(3,056-2,56)=2,015-0,496=1,519
6.6,75+3,25-7,168=2,832
7.8,6+2,51+2,4=13,51