## sapphers 2 years ago (sqrt2x+13) - 15 = x

1. Mertsj

Add 15 to both sides and then square both sides.

2. sapphers

I'm still kind of confused

3. Mertsj

Did you add 15 to both sides?

4. sapphers

Yeah, I did.

5. Mertsj

What did you get?

6. sapphers

$\sqrt{2x+13} = x + 15$

7. Mertsj

What do you get if you square the left side?

8. Mertsj

$(\sqrt{2x=13})^2= ?$

9. Mertsj

Sorry. I meant + 13 not =

10. TheViper

$\large{\sqrt{2x+13}-15=x}$$\large{\sqrt{2x+13}=x+15}$Now squaring both sides we get$\large{2x+13=x^2+225+30x}$

11. Mertsj

You must not square each side. So now it will look like this: $(\sqrt{2x+13})^2=(x+15)^2$

12. Mertsj

ok. Too many cooks. Good bye

13. TheViper

bye :)

14. sapphers

Thanks for leaving I guess... @Mertsj @TheViper are you leaving too or saying goodbye to the other guy?

15. TheViper

no

16. sapphers

Okay haha

17. TheViper

$\large{2x+13=x^2+225+30x}$$\large{\implies x^2+30x-2x+225-13=0}$$\large{\implies x^2+28x+212=0}$Now solve it by factoring :)

18. sapphers

You two were both telling me different things. How do I know that yours it right?

19. TheViper

We are telling same but concentrate on mine because I m here to help you :)

20. Mertsj

It won't factor. You'll have to use the quadratic formula.

21. sapphers

I tried factoring and it didn't work. So I plug x^2 + 28x + 212 into the quadratic formula?

22. Mertsj

yes

23. TheViper

yup :)

24. TheViper

I think it should be $$-14+2i$$ $$\&$$ $$-14-2i$$

25. TheViper

Check ur calculation again :)