Posted by Jack on .
solve
(x+16)*(x19)*(x+3)>0
The soltion set is{x }
I do not understand this one.

algebra 
drwls,
The (x+16)*(x19)*(x+3) function is zero at x = 16, 3 and 19.
It is >0 if x>19 and also if 16>x>3
check:
for x = 10, 6 x(29)x(7) = +1218
for x=20, 36*1*23 = +828
Somehow you put that into "solution set" language.