SOLUTION: {{{x^3 + 2x^2 - 9x = 18}}}

Algebra ->  Quadratic Equations and Parabolas  -> Quadratic Equations Lessons  -> Quadratic Equation Lesson -> SOLUTION: {{{x^3 + 2x^2 - 9x = 18}}}      Log On


   

Question 164069: x%5E3+%2B+2x%5E2+-+9x+=+18
Answer by Edwin McCravy(20055) About Me  (Show Source):
You can put this solution on YOUR website!
x%5E3+%2B+2x%5E2+-+9x+=+18

x%5E3+%2B+2x%5E2+-+9x+-+18=0

Factor x%5E2 out of the first two terms:

x%5E2%28x+%2B+2%29+-+9x+-+18=0

Factor -9 out of the last two terms:

x%5E2%28x+%2B+2%29+-+9%28x+%2B2%29=0

Factor %28x%2B2%29 out of each term:

%28x+%2B+2%29%28x%5E2+-+9%29=0

Factor the second parentheses as the difference of two squares:

%28x+%2B+2%29%28x-3%29%28x%2B3%29=0

Use the zero-factor principle:


   
Edwin