Question

ДАЮ 30 БАЛЛОВ!!! СРОЧНО
если f(x)=6x+3/x-2+1/4, то чему равен f(x)=17?​

Answer 1

Ответ:

$x_{1} = \frac{25+\sqrt{497} }{16}$                           $x_{2} = \frac{25-\sqrt{497} }{16}$

Объяснение:

$17=6x+\frac{3}{x} -2+\frac{1}{4}\\\\17=6x+\frac{3}{x} -\frac{7}{4} \\\\17 - 6x-\frac{3}{x} +\frac{7}{4} =0\\\\\frac{75}{4} -6x-\frac{3}{x} =0\\\\\frac{75x-24x^{2} - 12}{4x} =0\\\\75x-24x^{2} - 12 =0\\\\8x^{2} - 25x + 4 = 0\\\\D=b^{2} - 4ac = (-25)^{2} - 4*8*4=625-128\\\\D=497\\\\x= \frac{25б\sqrt{497}}{16} \\\\x_{1} =\frac{25+\sqrt{497}}{16}\\x_{2} =\frac{25-\sqrt{497}}{16}$