1. anonymous

2. anonymous

no solution since the y-value of a square root function must be positive

3. Mertsj

$-5\sqrt{x-9}-7=23$

4. Mertsj

$-5\sqrt{x-9}=30$

5. Mertsj

$\sqrt{x-9}=-6$

6. Mertsj

The positive square root of a number cannot be negative. So just like moneybird said.

7. anonymous

Couldnt it x be 27?

8. Mertsj

$-5\sqrt{27-9}-7=23$

9. Mertsj

Is that s true sentence?

10. anonymous

Oops, i mean 45

11. Mertsj

$-5\sqrt{45-9}-7=23$

12. anonymous

since the square root of 36 is 6 and -6

13. Mertsj

Is that true?

14. anonymous

yes

15. Mertsj

But the symbol indicates the POSITIVE root of 36

16. anonymous

what symbol?

17. Mertsj

|dw:1327710340814:dw|

18. anonymous

how do you know it means principle square root?

19. Mertsj

Because it does not say +/-

20. anonymous

oh, okay, that makes sense, thanks

21. Mertsj

What does "3" mean? Positive 3 or negative 3 or both?

22. anonymous

I don't think that is related... I'm just saying that -6^2 and 6^2 both equal 36

23. Mertsj

It is related. the symbol does not indicate a sign so it is understood to be the positive root.

24. Mertsj

and also -6^2=-36 wheras (-6)^2=36

25. anonymous

Oh wow, you are right, I immediately understood it to be positive, nice job. And you know i meant (-6)