## anonymous 3 years ago solving a radical equation

1. anonymous

2. anonymous

2x+15=5 2x=-10 x=-5, just square on both sides

3. anonymous

4. HELP!!!!

-5

5. anonymous

which one were you referring too? @HELP!!!!

6. HELP!!!!

the first one

7. anonymous

Hey, @itsjustme_lol. Given your second equation, $-5\sqrt{x-9} - 7 = 23$Since you're dealing with integers that can be divided and multiplied by each other and still result in even integers, it doesn't have to get nasty. <*hint* So, do you have any clue as to do next?

8. anonymous

x = -6 this is the answer i came up with

9. anonymous

Okay. Just to get a general idea of how you think and to make things easier for the future, let's say we have $2\sqrt{x + 4} - 4 = 8$What would be the first thing you would do, given a square root times something, and two numbers that can be added together?

10. anonymous

Ugh. I don't want to get bogged down, nevermind. Okay, so just as a general idea, if you ever have a square root with multiple terms that's being multiplied something, and you can't just square everything without anything getting "ugly" because of how squaring stuff might affect other numbers, almost always, the best thing for you to do is add like terms. In your problem, it would be adding negative seven to the side with twenty-three. Then you would get thirty. From this point, you have a square root with a coefficient, and all of that equals 30. From there, you can divide by that coefficient, and then square everything. Then you can solve for x.

11. anonymous

so x=45?

12. anonymous

Yes!

13. anonymous

thanks :D

14. anonymous

Np dude.

15. mathstudent55

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16. anonymous

Oh, crap. You're right. I totally missed that.

17. anonymous

thankyou

18. mathstudent55

Np, I'm glad I caught it.

19. anonymous

20. mathstudent55

Also, whenever you square both sides of an equation, you must check every solution bec squaring both sides can introduce extraneous solutions.

21. anonymous

its ok! at least you know that you made a mistke

22. anonymous
23. HELP!!!!

lol thats why it "open" study