Question 156337
5x^2-3x is greater than or equal to 8
first we find roots of 5x^2-3x-8=0

{{{x = (3 +- sqrt( (-3)^2-4*5*(-8) ))/(2*5) }}} =
{{{x = (3 +- (13))/(10) }}} 
roots are -1 and 1.6
5x^2-3x is greater than or equal to 8 when
5x^2-3x-8 is greater than or equal to 0

sign of 5x^2-3x-8 is    +++++++0- - - - - -0+++++++++
                              -1           1.6
(press show source to see the sign better)
then Solution set is: (-inf,-1]U[1.6,inf)