1. 4и6 5и3
2. а
3.3
................
2 2/9 (ты можешь скачать калькулятор Дробей, очень удобно)
<span>(38+b)*12=840</span>
<span>38+b=840:12</span>
<span>38+b=70</span>
<span>b=70-38</span>
<span>b=32</span>
<span>14(p-30)=630</span>
<span>р-30=630:14</span>
<span>р-30=45</span>
<span>р=30+45</span>
<span>р=75</span>
<span>(43-s)*17=289</span>
<span>43-s=289:17</span>
<span>43-s=17</span>
<span>s=43-17</span>
<span>s=26</span>