Help with summer calculus packet?

Question

solve for x where x is a real number:

1. x^2 -2x - 15 < or = 0

Answer 1

x^2-2x-15 is a parabola curving upward, so if it is &lt; 0, it will be between two numbers.  Just use the quadratic equation or factor...

(x - 5)(x + 3) = 0

x = 5 or x = -3

Therefore

-3 &lt;= x &lt;= 5   (ANSWER)

&quot;&lt;=&quot; means less than or equal to.

Take care,

David

Answer 2

The rest of the question doesn&#039;t make sense to me where you have &quot;&lt;=0&quot;.  Start breaking it down first, you get (x-3)(x+5).  That leads to x=3, x=-5

Answer 3

Question is x^2 -2x - 15 ≤ 0

=&gt; ( x - 5 ) ( x + 3 ) ≤ 0

=&gt; -3 ≤ x ≤ 5