## osanseviero one year ago How to solve this?

1. osanseviero

$10a ^{2}-20a+8$ Do I need to use the general formula?

2. hartnn

solve ? if you want to solve you need an equation (with =0) do you want to factor this ?

3. osanseviero

yep

4. hartnn

yes what ? factor or solve ?

5. osanseviero

solve

6. hartnn

then yes, you'll need a quadratic formula

7. hartnn

Compare your quadratic equation with $$ax^2+bx+c=0$$ find $a=...?\\b=...?\\c=...?\\$ $\\ \sqrt{b^2-4ac}=...?$ then the two roots of x are: $$\huge{x_{1,2}=\frac{-b \pm \sqrt{b^2-4ac}}{2a}}$$

8. osanseviero

$\frac{ -20\pm4\sqrt{5} }{ 20 }$

9. osanseviero

Am I correct until here?

10. hartnn

b =-20 right ? so, -b =+20

11. osanseviero

Ok...and then?

12. hartnn

yeah, then factor out the '4' from the numerator

13. osanseviero

Thanks! Got it!

14. hartnn

welcome ^_^