SOLUTION: solve 5x^3-18x^2+9x

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Question 650018: solve 5x^3-18x^2+9x

Answer by MathLover1(20850) About Me  (Show Source):
You can put this solution on YOUR website!

5x%5E3-18x%5E2%2B9x
x%285x%5E2-18x%2B9%29.....replace -18x with -3x-15
x%285x%5E2-3x-15x%2B9%29....group
x%28%285x%5E2-3x%29-%2815x-9%29%29
x%28x%285x-3%29-3%285x-3%29%29
x%28x-3%29%285x-3%29
now, if you set it equal to zero, you can solve for x
x%28x-3%29%285x-3%29=0
roots:
x=0 ........first solution

if %28x-3%29=0...->...x=3....second solution
if %285x-3%29=0...->...5x=3..->...x=3%2F5..second solution