## anonymous 4 years ago Solve.. 3x^3 - 23x^2 +7x +5

1. anonymous

$(1+3 x) \left(5-8 x+x^2\right)$

2. anonymous

Hi Math, how do we solve this?

3. Hero

Good job posting the steps Fool

4. anonymous

i mean what is x equal to?

5. anonymous

i think i know the answer now :) thanks!

6. Hero

cherrydrops, in order to solve it, it has to be an equation. What you have posted is simply an expression.

7. anonymous

are there 3 answers for x? omg the expression has an ' = 0 ' at the right. oops!

8. Hero

ya, you forgot to include the = 0

9. anonymous

thank you

10. Hero

FFM, do you mind posting the steps?

11. anonymous

I.. don't think he's there :)

12. Hero

Yeah, he magically disappeared without posting the steps

13. anonymous

Heheh. yeah :(

14. Hero

Okay, I have it finally

15. Hero

Are you ready for the steps?

16. Hero

3x^3-23x^2+7x+5 3x^3-24x^2+x^2+15x-8x+5 3x^3-24x^2+15x+x^2-8x+5 3x(x^2-8x+5)+1(x^2-8x+5) (x^2-8x+5)(3x+1)

17. Hero

Tedious, but it works

18. anonymous

wow.. ;) thanks

19. Hero

now you can do this: (x^2-8x+5)(3x+1) = 0 x^2-8x + 5 = 0 3x+1 = 0 and solve for x

20. anonymous

Aahh i'm lost even before i got to the third step.. ;l how did 3x^3-23x^2+7x+5 become 3x^3-24x^2+x^2+15x-8x+5?

21. Hero

-24x + x^2 = -23x 15x-8x = 7x

22. anonymous

right... ;