Найти интервалы убывания функции y = 0,8x<sup>5</sup> + x<sup>4</sup> - 16x<sup>3</sup> + 15:<img src="/close/store/examRes/%7B9B820A29-D263-43B6-ADA5-062E1898D27C%7D/prf8.4.gif" /><img src="/close/store/examRes/%7B9B820A29-D263-43B6-ADA5-062E1898D27C%7D/prf8.1.gif" /><img src="/close/store/examRes/%7B9B820A29-D263-43B6-ADA5-062E1898D27C%7D/prf7.3.gif" /><img src="/close/store/examRes/%7B9B820A29-D263-43B6-ADA5-062E1898D27C%7D/prf7.2.gif" /> <img src="/img/e4/32cb6ade6f014639abcd9723be.gif" />, <img src="/img/f0/9505b6129c46c2622038555b3a.gif" />, <img src="/img/1c/46c82bea249f3b3211445a86fb.gif" />, <img src="/img/29/6ff912fca8fef12bd73b92ed6a.gif" />