We cannot do crossing over
Let's rearrange the inequality
3/(x+1)<=3
3/(x+1)-3<=0
(3-3x-3)/(x+1)<=0
(-3x)/(x+1)<=0
Let f(x)=(-3x)/(x+1)
Let's build the sign chart
color(white)(aaaa)xcolor(white)(aaaa)-oocolor(white)(aaaaaa)-1color(white)(aaaaaaaa)0color(white)(aaaaa)+oo
color(white)(aaaa)-3xcolor(white)(aaaaaa)+color(white)(aaaa)||color(white)(aaaa)+color(white)(aa)0color(white)(aa)-
color(white)(aaaa)x+1color(white)(aaaaa)-color(white)(aaaa)||color(white)(aaaa)+color(white)(aa)0color(white)(aa)+
color(white)(aaaa)f(x)color(white)(aaaaaa)-color(white)(aaaa)||color(white)(aaaa)+color(white)(aa)0color(white)(aa)-
Therefore,
f(x)<=0 when x in (-oo,-1) uu [0,+oo) graph{3/(x+1)-3 [-19.3, 21.26, -12.45, 7.82]}