17+7=24
14+7=21
16+7=23
18+7=25
21-17=4
21-14=7
21-16=5
21-18=3
(х+4 9/11)-5 6/11=1 8/11
(х+53/11)-61/11=19/11
х+53/11=19/11+61/11
х+53/11=80/11
х=80/11-53/11
х=27/11
х=2 5/11
13 2/9-(7 5/9+у)=3 5/9
119/9-68/9+у=32/9
у=32/9-119/9+68/9
у=-19/9
у=-2 1/9
=(5+8/14):13:28=13:14*28/13=2
1)8,35+2/5x=9 3/4
8 35/100+2/5х=9 3/4
835/100+2/5х=39/4
2/5х=39/4- 835/100
2/5х=975/100-835/100
2/5х=140/100
2/5х=7/5
х=7/5 : 2/5
х=7/5*5/2
х=7/2=3 1/2
2)9,625 - 15/x+4=7 1/8
9 625/1000-15/х=7 1/8
9625/1000-15/х=7 1/8 (9625/1000 сократим на 125)
77/8-15/х=57/8
15/х=77/8-57/8
15/х=20/8
х=15 : 20/8
х=15* 8/20
х=6