[tex] 3x ^2 + 13x - 10 \leq 0 \\ \\first\ we \ solve: \\ 3x ^2 + 13x - 10\\ (x + 5) (3 x - 2)=0 \\x+5=0 \ \ or \ \ 3x-2=0 \\x=-5\ \ or \ \ 3x= 2 \\ x=-5\ \ or \ \ x= \frac{2}{3}[/tex]
a > 0 open for up .
So we know that the curve is u-shaped and that it crosses
the x-axis at [tex]x=- \frac{2}{3} and x=-5.[/tex]
The curve is less than zero : [tex]x \geq -5 \ and \ x \leq \frac{2}{3}[/tex]
