Answer:
Kathy made a mistake between step 2 and 3
x-2=0 is correct but she solved the equation wrong.
The answer should be x=2, x=-16 because:
x-2=0
+2 +2
x=2
(The 16 is correct)
Remember ax^2 + bx + c
Everything leading up to Step 2 is correct (-2 plus 16 equals the b term and -2 times 18 equals the c term).*
*Remember that this rule only applies when the a term equivalent to 1.
When the term isn't 1, you can try factoring or using the quadratic formula.