Question 901150
Suppose f(x)=(x−2)(x+9).
(a) For which values of x is the function f(x) positive? Enter your answer using inequalities.
(x-2)(x+9)>0
number line:
<..+..-9..-..2..+..>
solution: (-&#8734;,-9) U (2,&#8734;)
..
(b) For which values of x is the function f(x) negative? Enter your answer using inequalities. 
(x-2)(x+9)<0
number line:
<..+..-9..-..2..+..>
solution: (-9,2)