How do I find the value of x?

**misiaizeska** · October 18th 2012, 08:57 AM

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I'm not sure how to delete this question - I had an error in my calculations but I managed to figure it out and there's no point in keeping this question up anymore

**HallsofIvy** · October 18th 2012, 09:23 AM

You perhaps have multiplied or subtracted incorrectly. $2(x- 2)(x- 3)(x+ 5)= 2(x^2- 5x+ 6)(x+ 5)$ $= 2(x^3-38x+ 30)= 2x^3- 38x+ 60= 120$ so that $2x^3- 38x- 60= 0$ , not "- 150". Dividing through by 2, $x^3- 19x- 30= 0$ . I notice that $(-2)^3- 19(-2)- 30= -8+ 38- 30= 0$ .

**misiaizeska** · October 18th 2012, 09:25 AM

Yep, this is exactly what I got wrong! For some reason I though f(x) = 210 instead of 120, not sure why I got my numbers mixed up. Thank you though!

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