Question 940866
{{{1-2x-3x^2<0}}} ...factor

{{{1-3x+x-3x^2<0}}}

{{{(1-3x)+(x-3x^2)<0}}}

{{{(1-3x)+x(1-3x)<0}}}

{{{(1-3x)(1+x)<0}}}

solutions:

{{{(1-3x)<0}}} if {{{1<3x}}} or {{{x>1/3}}}

{{{(1+x)<0}}} if {{{x<-1}}} or {{{x<-1}}}


solution interval:

({{{-infinity}}},{{{-1}}}) U ({{{1/3}}},{{{infinity}}})

{{{graph( 600, 600, -10, 10, -10, 10,1-2x-3x^2) }}}

shade the region below x-axis and left the line where {{{x<-1}}}, then also shade the region below x-axis and right from the line where {{{x>1/3}}}