SOLUTION: I need help in factoring this equation! I also need it to be shown to me step by step because I dont know how to solve it! {{{ 2x^3-x^2-18x+9=0 }}}

Algebra ->  Quadratic Equations and Parabolas  -> Quadratic Equation Customizable Word Problems -> SOLUTION: I need help in factoring this equation! I also need it to be shown to me step by step because I dont know how to solve it! {{{ 2x^3-x^2-18x+9=0 }}}      Log On


   

Question 293833: I need help in factoring this equation! I also need it to be shown to me step by step because I dont know how to solve it!
+2x%5E3-x%5E2-18x%2B9=0+
Answer by nerdybill(7384) About Me  (Show Source):
You can put this solution on YOUR website!
+2x%5E3-x%5E2-18x%2B9=0+
.
Apply the technique of "grouping" -- sometimes you may have to reorder terms but in your case you do not:
.
+%282x%5E3-x%5E2%29+-+%2818x%2B9%29+=0+
.
Now, factor each expression inside the parenthesis:
+x%5E2%282x-1%29+-+9%282x%2B1%29+=0+
.
+%282x-1%29%28x%5E2-+9%29+=0+
.
Check whether or not you can factor further. In this case, we see a "difference of squares":
+%282x-1%29%28x-3%29%28x%2B3%29+=0+
.
From here, we see that our solutions are:
x = {1/2, 3, -3}