7 задача 3
8 задача2
15 задача 4
5428*7= 37996 ц это сколько собрали на втором участке
К общему знаменателю приводм, получаем
![\frac{6}{14} : \frac{15}{14} =0.4*x](https://tex.z-dn.net/?f=+%5Cfrac%7B6%7D%7B14%7D+%3A+%5Cfrac%7B15%7D%7B14%7D+%3D0.4%2Ax)
Решаю
По основному свойству пропорции
х=
![\frac{\frac{15}{14} *0.4}{ \frac{6}{14} }](https://tex.z-dn.net/?f=+%5Cfrac%7B%5Cfrac%7B15%7D%7B14%7D+%2A0.4%7D%7B+%5Cfrac%7B6%7D%7B14%7D+%7D++)
х=
![\frac{15}{14} *0.4* \frac{14}{6} =0.4* \frac{15}{6} = \frac{6}{6} =1 ](https://tex.z-dn.net/?f=+%5Cfrac%7B15%7D%7B14%7D+%2A0.4%2A+%5Cfrac%7B14%7D%7B6%7D+%3D0.4%2A+%5Cfrac%7B15%7D%7B6%7D+%3D+%5Cfrac%7B6%7D%7B6%7D+%3D1%0A+)
1 <span>2/9</span>+3 <span>1/3</span>=<span>1 · 9 + 2/9</span>+<span>3 · 3 + 1/3</span>=<span>11/9</span>+<span>10/3</span>=<span>1 · 111 · 9</span>+<span>3 · 103 · 3</span>=<span>119</span>+<span>309</span>=<span>11 + 309</span>=<span>419</span>=4 <span>5/9<span>
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