How do you solve ((x+3)(x+5))/(x+2)>=0?

1 Answer
Mar 17, 2017

The solution is x in [-5,-3] uu]-2, +oo[

Explanation:

We solve this inequality with a sign chart

Let f(x)=((x+3)(x+5))/(x+2)

The domain of f(x) is D_f(x)=RR-{-2}

Let build the sign chart

color(white)(aaaa)xcolor(white)(aaaa)-oocolor(white)(aaaa)-5color(white)(aaaa)-3color(white)(aaaaaa)-2color(white)(aaaaaaa)+oo

color(white)(aaaa)x+5color(white)(aaaaaa)-color(white)(aaaa)+color(white)(aaaa)+color(white)(aaaa)||color(white)(aaaa)+

color(white)(aaaa)x+3color(white)(aaaaaa)-color(white)(aaaa)-color(white)(aaaa)+color(white)(aaaa)||color(white)(aaaa)+

color(white)(aaaa)x+2color(white)(aaaaaa)-color(white)(aaaa)-color(white)(aaaa)-color(white)(aaaa)||color(white)(aaaa)+

color(white)(aaaa)f(x)color(white)(aaaaaaa)-color(white)(aaaa)+color(white)(aaaa)-color(white)(aaaa)||color(white)(aaaa)+

Therefore,

f(x)>=0 when x in [-5,-3] uu]-2, +oo[