Найти интервалы убывания функции y = 20x<sup>3</sup> - 2x<sup>5</sup> - 12,5x<sup>4</sup> + 7:<img src="/close/store/examRes/%7B9B820A29-D263-43B6-ADA5-062E1898D27C%7D/prf32.1.gif" /><img src="/close/store/examRes/%7B9B820A29-D263-43B6-ADA5-062E1898D27C%7D/prf32.4.gif" /><img src="/close/store/examRes/%7B9B820A29-D263-43B6-ADA5-062E1898D27C%7D/prf32.2.gif" /><img src="/close/store/examRes/%7B9B820A29-D263-43B6-ADA5-062E1898D27C%7D/prf32.3.gif" /> <img src="/close/store/examRes/%7B9B820A29-D263-43B6-ADA5-062E1898D27C%7D/prf32.1.gif" />, <img src="/close/store/examRes/%7B9B820A29-D263-43B6-ADA5-062E1898D27C%7D/prf32.2.gif" />, <img src="/close/store/examRes/%7B9B820A29-D263-43B6-ADA5-062E1898D27C%7D/prf32.3.gif" />, <img src="/close/store/examRes/%7B9B820A29-D263-43B6-ADA5-062E1898D27C%7D/prf32.4.gif" />