## kandsbbf Group Title Find the real solutions of the equation by graphing. –8x3 – 17x2 + 7x = 0 one year ago one year ago

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1. kandsbbf Group Title

@zepdrix

2. kandsbbf Group Title

0, –2.48, 0.35 –2.48 –2.48, 0.35 0, 2.48, –0.35

3. kandsbbf Group Title

@zepdrix

4. zepdrix Group Title

lol once is enough ^^ sorry I'm also helping someone else so it's hard to get away XD

5. kandsbbf Group Title

i didn't mean too lol my cp is slow.. thought u didn't get it

6. zepdrix Group Title

$\large -8x^3-17x^2+7x=0$See how EVERY term has an X in it? Let's start by factoring an X out of each term.$\large x(-8x^2-17x+7)=0$

7. zepdrix Group Title

I know they said to solve by GRAPHING, but I'm not exactly sure how you would go about doing that. Do they mean by using a calculator?

8. zepdrix Group Title

Graphing Calculator*?

9. zepdrix Group Title

Anyway doing it this way, if we apply the Zero Factor Property, we'll set each factor equal to 0 giving us,$\large x=0 \qquad \text{and}\qquad -8x^2-17x+7=0$

10. kandsbbf Group Title

maybe but i don't have one and their are actual graphs as the answersbut i just gave u the points.....

11. kandsbbf Group Title

okayy

12. zepdrix Group Title

From here, we can immediately cancel out two of the options, because it has to be one of the choices with x=0.

13. zepdrix Group Title

To find the other two roots, we can throw the quadratic part into the Quadratic Formula.$\large ax^2+bx+c=0 \qquad \rightarrow \qquad x=\frac{-b \pm \sqrt{b^2-4ac}}{2a}$

14. zepdrix Group Title

$\large -8x^2-17x+7=0 \qquad \rightarrow \qquad x=\frac{17 \pm \sqrt{17^2-4(-8)(7)}}{2(-8)}$

15. zepdrix Group Title

Hopefully I plugged that in correctly. You can punch that into your calculator and hopefully get something that's listed :O