Question 62263
3x^2-x-4<=0 
(3x-4)(x+1)<=0
The equality is satisfied if x=3/4 or x=-1
Draw a number line and plot the values x=-1 and x=3/4
That creates three intervals on the number line:
I: (-inf,-1)
II: (-1,3/4)
III; (3/4,inf)
Test a point in each interval to see where
the solution set for the inequality lies.
I: test x=-10 in 3x^2-x-4<0; it does not work
II: test x=0 in the same; it works
III: test x=10 in the same; it does not work
SOLUTION:
-1<=x<=3/4
Cheers,
Stan H.