-15,76+34,22-24,72+4,43-81,16=-82,99
5*20=100 ну и все просто и легко
(x-1 2/5):10+7 5/12=9
<span> <span> (x-1 2/5):10=9-7 5/12 </span></span>
<span><span> </span></span><span><span> <span>(x-1 2/5):10=8 12/12-7 5/12</span></span> </span><span> </span>
<span> <span> (x-1 2/5):10=1 7/12 </span></span>
<span><span> </span></span><span>x-1 2/5=19/12*10</span>
<span>x=190/12+7/5</span>
<span>x=95/6+7/5</span>
<span>x=475/30+42/30</span>
<span>x=517/30</span>
<span>x=17 7/30</span>
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Расстояние между 7 елками =(7-1) *2= 6*2=12м