Let f(x)=(x+8)(x+2)(x-3)f(x)=(x+8)(x+2)(x−3)
Let's do the sign chart
color(white)(aaaa)aaaaxxcolor(white)(aaaa)aaaa-oo−∞color(white)(aaaa)aaaa-8−8color(white)(aaaa)aaaa-2−2color(white)(aaaa)aaaa33color(white)(aaaa)aaaa+oo+∞
color(white)(aaaa)aaaax+8x+8color(white)(aaaaa)aaaaa-−color(white)(aaaa)aaaa++color(white)(aaaa)aaaa++color(white)(aaaa)aaaa++
color(white)(aaaa)aaaax+2x+2color(white)(aaaaa)aaaaa-−color(white)(aaaa)aaaa-−color(white)(aaaa)aaaa++color(white)(aaaa)aaaa++
color(white)(aaaa)aaaax-3x−3color(white)(aaaaa)aaaaa-−color(white)(aaaa)aaaa-−color(white)(aaaa)aaaa-−color(white)(aaaa)aaaa++
color(white)(aaaa)aaaaf(x)f(x)color(white)(aaaaaa)aaaaaa-−color(white)(aaaa)aaaa++color(white)(aaaa)aaaa-−color(white)(aaaa)aaaa++
Therefore,
f(x)>=0f(x)≥0, when x in [-8,-2] uu [3, +oo[ x∈[−8,−2]∪[3,+∞[
graph{(x+8)(x+2)(x-3) [-154.2, 146, -60.4, 89.8]}