Question

Is anyone good with square roots? I need a lot of help

Answer 1

Yes.

Answer 2

I know a bit.

Answer 3

What kinda help do you need with square roots so we can quickly help you out !

Answer 4

oh great. ok so my first one is sqrt x = x - 20

Answer 5

where did everyone go?
\[\sqrt{x}=x-20\]square both sides to get
\[x=(x-20)^2=x^2-40x+400\]

Answer 6

Can you proceed from there kika?

Answer 7

How does the 40x get there?

Answer 8

FOIL of (x-20)(x-20)

Answer 9

then solve
\[x^2-41x+400=0\] which is sort of annoying but you can factor it

Answer 10

ok i think i understand so far.

Answer 11

\((x-20)^2=(x-20)(x-20)=x^2-40x+400\)

Answer 12

aka multiply

Answer 13

I hear you satellite. I'm just talking the familiar lingo. (At least at my schools)

Answer 14

You are very helpful satelite

Answer 15

Yeah, So i have some more complicated ones i need help with too so dont leave lol

Answer 16

then by some miracle
\[x^2-41x+400=0\] factors as
\[(x-25)(x-16)=0\] so you have two choices, \(x=25\) or \(x=16\) now you have to check and see if they work or not

Answer 17

how did you do that?!

Answer 18

by which i mean you have to check in the original equation
\[\sqrt{x}=x-20\]
if \(x=25\) then you get
\[\sqrt{25}=25-20?\]
\[5=5\checkmark\]

Answer 19

on the other hand if \(x=16\) you get
\[\sqrt{16}=16-20?\]
\[4=-4\] NO

Answer 20

How did he factor the trinomial?

Answer 21

no i mean how did you factor it?

Answer 22

so only one answer, namely \(x=25\)

Answer 23

ooh how did i factor \[x^2-41x+400=0\]??

Answer 24

Am I getting in the way satellite?

Answer 25

is that the question?

Answer 26

nah i wasn't paying attention to the question, my fault

Answer 27

yeah how do i factor

Answer 28

personally? i cheat

Answer 29

Hahahaha

Answer 30

how??

Answer 31

http://www.wolframalpha.com/input/?i=x^2-41x%2B400%3D0

this one was cooked to be easy, though
since it was pretty clear that your answer was going to be a perfect square

Answer 32

It's really not easy satellite to explain I know

Answer 33

To explain how you factor out

Answer 34

no i think i explained my method of cheating quite well

Answer 35

thats fine, i have no problem cheating

Answer 36

Because it's just trial and error

Answer 37

factoring is for donkeys

Answer 38

"two numbers whose product is 400 and whose some is -41"
you have a few choices, but none so nice as the perfect squares -25 and -16

Answer 39

That we already know i think what we are intereted in whats the easiest cheating way of getting them

Answer 40

Ok, so the first step is to FOIL the right side and take off the square root. Then put the trinomial into the wolfram website and choose the option that works?

Answer 41

Hahahahahah

Answer 42

When you sitting in the exams you won't have access to wolfram website

Answer 43

My class already ended but i didnt pass so i have until 8am to get my grade up 3%

Answer 44

no finals for me!

Answer 45

Thats so funny !

Answer 46

What do you need to do to go up 3%?

Answer 47

I have to do like 5 assignments

Answer 48

How long are the assignments?

Answer 49

mmm around 15 problems

Answer 50

http://www.wolframalpha.com/input/?i=sqrt%28x%29%3Dx-20

Answer 51

What can I do to help? Understand that I will most likely try to make you work. I want you to survive next year. I won't just give answers and tell you to let a website work.

Answer 52

I understand. Im going to relearn everything this summer, i just dont want an F to go on my permanent record

Answer 53

I don't want that either. Let's work. I won't run off.

Answer 54

Thanks!! Ok, so i have sqr x=x-12 and i factored it to x-12x+144 and now what

Answer 55

The website isnt liking that

Answer 56

When you squared the left side you got x
When you squared the right side you should have gotten x^2 -24x +144.

Do you see why?

Answer 57

yeah! ok so lemme try that in the website

Answer 58

The website? Is that where you show your work for the assignment?

Answer 59

No i was talking the the wolfram website but it isnt really working.

Answer 60

So what do i do after x^2-12x+144?

Answer 61

Gather everything on the x^2 side so you have: trinomial = 0

Answer 62

ok so x^2-12x+144=0

Answer 63

\[x = x^{2} - 24x + 144\]

\[0 = x^{2} - 25x + 144\]

This is where we should be.

Answer 64

ok, then i just solve it like a regular equations right?

Answer 65

True. What will you do?

Answer 66

its 16!!!!!!!

Answer 67

and ......

Answer 68

ok, so that was the simple one....
@RT{5x+19}-x=5

Answer 69

oops! thats supposed to be a square root sign

Answer 70

On the last problem, did you see that there were two solutions 9, 16 but only 16 really worked in the original problem. 9 was an extraneous solution.

Answer 71

yes i tried them both but 9 didnt work :)

Answer 72

sqrt(5x+19) - x = 5 ?

Answer 73

The 5x+19 are both under the square root sign

Answer 74

When dealing with radicals, you always try to get the radical alone and everything else on the other side. Also, with multiple radicals, you get radicals on opposite sides of the equation.

Answer 75

ok

Answer 76

So.....what are you thinking?

Answer 77

that this is going impossible haha. sqr5x-19=x+5

Answer 78

Fine. Now you should proceed like before.

Answer 79

square everything?

Answer 80

Right. Left side just loses the radical.

Answer 81

right. 5x-19=x^+25

Answer 82

(x+5)(x+5) -----> x^2 ______ +25

Something is missing.

Answer 83

you lost me

Answer 84

Multiply each thing in the first parentheses by each thing in the second.

x*x + 5*x +5*x + 5*5

Answer 85

x^2+10x+35

Answer 86

+ 25

Now get everything on one side and factor.

Answer 87

thats what i meant

Answer 88

ok thanks for the help.

Answer 89

What did you get?

Answer 90

i didnt get anything. im still confused but i think i will figure it out. thanks for trying to help

Answer 91

You had the sides.

When you combined like terms on one side you should have: x^2 +5x +6=0

Answer 92

thanks