Ответ:
Пошаговое объяснение:
![\displaystyle\\49^{-\frac{1}{2}}*(\frac{1}{7})^{-2}+2^{-1}*(-2)^{-2} =\\\\(7^2)^{-\frac{1}{2}}*7^2+2^{-1}*2^{-2} =7^{-1+2}+2^{-1-2}=7\frac{1}{8} =7.125\\ \\ \\ \\ y^\frac{7}{4}*\sqrt[3]{y^2}*y^\frac{1}{6} =y^{\frac{7}{4} +\frac{2}{3} +\frac{1}{6}} =y^\frac{21+8+2}{12} =y^\frac{31}{12} \\\\ \\ \\ 4^\frac{1}{3} *2^{1\frac{1}{3}}:4^{- \frac{1}{3}}=2^\frac{2}{3}*2^\frac{4}{3} *2^\frac{2}{3} =2^\frac{2+4+2}{3} =2^\frac{8}{3} =4*2^\frac{2}{3} \\ \\](https://tex.z-dn.net/?f=%5Cdisplaystyle%5C%5C49%5E%7B-%5Cfrac%7B1%7D%7B2%7D%7D%2A%28%5Cfrac%7B1%7D%7B7%7D%29%5E%7B-2%7D%2B2%5E%7B-1%7D%2A%28-2%29%5E%7B-2%7D%20%3D%5C%5C%5C%5C%287%5E2%29%5E%7B-%5Cfrac%7B1%7D%7B2%7D%7D%2A7%5E2%2B2%5E%7B-1%7D%2A2%5E%7B-2%7D%20%3D7%5E%7B-1%2B2%7D%2B2%5E%7B-1-2%7D%3D7%5Cfrac%7B1%7D%7B8%7D%20%3D7.125%5C%5C%20%5C%5C%20%5C%5C%20%5C%5C%20y%5E%5Cfrac%7B7%7D%7B4%7D%2A%5Csqrt%5B3%5D%7By%5E2%7D%2Ay%5E%5Cfrac%7B1%7D%7B6%7D%20%3Dy%5E%7B%5Cfrac%7B7%7D%7B4%7D%20%2B%5Cfrac%7B2%7D%7B3%7D%20%2B%5Cfrac%7B1%7D%7B6%7D%7D%20%3Dy%5E%5Cfrac%7B21%2B8%2B2%7D%7B12%7D%20%3Dy%5E%5Cfrac%7B31%7D%7B12%7D%20%5C%5C%5C%5C%20%5C%5C%20%5C%5C%204%5E%5Cfrac%7B1%7D%7B3%7D%20%2A2%5E%7B1%5Cfrac%7B1%7D%7B3%7D%7D%3A4%5E%7B-%20%5Cfrac%7B1%7D%7B3%7D%7D%3D2%5E%5Cfrac%7B2%7D%7B3%7D%2A2%5E%5Cfrac%7B4%7D%7B3%7D%20%2A2%5E%5Cfrac%7B2%7D%7B3%7D%20%3D2%5E%5Cfrac%7B2%2B4%2B2%7D%7B3%7D%20%3D2%5E%5Cfrac%7B8%7D%7B3%7D%20%3D4%2A2%5E%5Cfrac%7B2%7D%7B3%7D%20%5C%5C%20%20%20%5C%5C)
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![a^m*a^n=a^{m+n}](https://tex.z-dn.net/?f=a%5Em%2Aa%5En%3Da%5E%7Bm%2Bn%7D)
1 сторона=70,2 см;
2 сторона=70,2:6=11,7 см.
А)(х+15)-8=17,х+15-8=17,х=17-15+8,х=10
б)(24-х)-21=10,24-х-21=10,х=10-24+21,х=-35
в)(45-у)+18=58,45-у+18=58,у=58-45-18,у=-5
г)(у-35)+12=32,у-35+12=32,у=32+35-12,у=55
1+5+9+15 решаем удобным способом 1+9+5+15=30
18+7+13+22
13+7+18+22=60