180 - abf = 124
180 - 124 = 76
76/2 = 38 - углы рб треугольника
38/2 = 19 - асl
Ответ: 19
<span>m(t) = m0·2</span><span>^(−t/T)</span>
<span>m0=200 <span>мг
</span></span><span>T=3 мин
</span>m(t) = <span>25 <span>мг
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t - ?
Подставляем в формулу </span></span><span>m(t) = m0·2<span>^(−t/T) </span>значения </span>m0, Т и m(t) :
<span>25 = 200·2</span><span><span>^(</span><span>− t/3)
</span></span>25 = 200/2<span>^(t/3)</span>
2<span>^(<span>t/3) = 200/25
</span></span>2<span>^(t/3) = 8</span>
2<span>^(<span>t/3) = 2³
</span></span><span>t/3 = 3
</span><span>t = 9
Ответ: 9 минут
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