Question 1123377
{{{6x^2-14x-4=0}}}

{{{3x^2-7x-2=0}}}

Zeros at  {{{(7+- sqrt(49+24))/6}}}
Mean that original equation has extreme y values at:
{{{(7+- sqrt(73))/6}}}
or
about  -0.257 and  +2.59


You might try Rational Roots Theorem to find any rational roots to help.  Maybe there is a root of original equation for x at 4.


{{{graph(400,400,-15,15,-20,10,2x^3-7x^2-4x)}}}