От перемены мест множителей значение произведение не меняется. Свойство степени: ![\displaystyle a^{m+n} =a^m\cdot a^n](https://tex.z-dn.net/?f=%5Cdisplaystyle%20a%5E%7Bm%2Bn%7D%20%3Da%5Em%5Ccdot%20a%5En)
![\displaystyle \frac{25x^2p}{y^3} \cdot \frac{y^6}{15x^8} =\frac{5x^2y^3\cdot 5py^3}{5x^2y^3\cdot 3x^6} =\boxed{\frac{5py^3}{3x^6}}](https://tex.z-dn.net/?f=%5Cdisplaystyle%20%5Cfrac%7B25x%5E2p%7D%7By%5E3%7D%20%5Ccdot%20%5Cfrac%7By%5E6%7D%7B15x%5E8%7D%20%3D%5Cfrac%7B5x%5E2y%5E3%5Ccdot%205py%5E3%7D%7B5x%5E2y%5E3%5Ccdot%203x%5E6%7D%20%3D%5Cboxed%7B%5Cfrac%7B5py%5E3%7D%7B3x%5E6%7D%7D)
(x-1)(x-3)(x+5)(x+7)=297((x – 1)(x + 5))((x – 3)(x + 7)) = 297;(x2 + 5x – x – 5)(x2 + 7x – 3x – 21) = 297;(x2 + 4x – 5)(x2 + 4x – 21) = 297.x2 + 4x = t, тогда :(t – 5)(t – 21) = 297.t2 – 21t – 5t + 105 = 297;t2 – 26t – 192 =0<span>t1=-6 и t2=32</span>x2 + 4x = -6 или x2 + 4x = 32x2 + 4x + 6 = 0 x2 + 4x – 32 = 0D = 16 – 24 < 0 D = 16 + 128 > 0 Нет корней x1 = -8; x2 = 4<span>Ответ: x1=-8 , x2=4</span>