<span> (17х+153):153=98
17х+153=98*153
17х+153=14994
17х=14994-153
17х=14841
х=14841:17
х=873</span>
<span>5 4/7 : 1 5/21 - (5 2/15 х 3/22 + 1 14/15) =1 13/15
</span>
<span>5 4/7 : 1 5/21=39/7*21/26=9/2
5 2/15*3/22=77/15*3/22=7/10
7/10+ 1 14/15=7/10+29/15=(21+58)/30=79/30
9/2-79/30=(135-79)/30=56/30=1 26/30=1 13/15
</span>
4600 кв.дм = 46 кв.м
1 кв.м = 100 кв.дм
4600 : 100 = 46 (кв.м)
5а * 8 = 80
5а = 80:8
5а =10
а=10:5
а=2