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0,2 * 2,6 + 6,89=<span>7.41</span><span>
1)</span><span>0,2 * 2,6 =0.52
2)0.52+6.89=7.41
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100:(45-х)=4
45-х=100:4
45-х=25
х=45-25
х=20
Проверка
100:(45-20)=4
4=4
Ответ X=+7;-7
<span>0,7*|x|-10=-5,1
</span><span>0,7*|x|=4.9
</span>|x|=4.9/0.7
|x|=7
(7х - 12)* 5/14 = 7х * 5/14 - 12* 5/14 = 5х/2 - 30/7 = 2,5х - 4 2/7