Question

Solve the equation by using the Square Root Property.

x^2 = 10x + 24

Answer 1

@hartnn

Answer 2

ok, so \(x^2-10x=24\)
the co-efficient of 'x' here is 10
divide it by 2 and square the result, what u get ?

Answer 3

***the co-efficient of 'x' here is -10

Answer 4

so it would be x^2-5x=24

Answer 5

no no..
the co-efficient of x is -10, right ?
divide it by 2, you get -5, but then square it, \(\large (-5)^2=...?\)

Answer 6

2.23

Answer 7

is that right????

Answer 8

umm...noo...how u got thta ?

Answer 9

i squared 5 isnt that what i was supposed to do

Answer 10

5^2 =25

Answer 11

oh i thought i was supposed to square root it not square my b now what

Answer 12

ohh...u took square root...we are supposed to square..

Answer 13

ok, we add 25 on both sides
\(x^2-10x+25=24+25\)
notice that left side is a perfect square! of ?

Answer 14

49

Answer 15

49 is right side, and is the square of 7
what about left side ?
x^2-10x+25 is squaree of ?

Answer 16

idk

Answer 17

\((x-5)^2 =... ?\)
can u find ?

Answer 18

x^2- 25

Answer 19

nopes, \((a+b)^2=a^2+2ab+b^2\)

so, \((x-5)^2 =x^2-10x+25\)
so here we have
\((x-5)^2=7^2\)
take square root on both sides!

Answer 20

ok

Answer 21

then what

Answer 22

im confused

Answer 23

did u take square root on both sides ? what u got ?

Answer 24

idk

Answer 25

\((x-5)^2=7^2 \implies x-5 = \pm 7 \\ x-5 =7 \quad \quad x-5=-7\)
get 2 values of 'x' from here!

Answer 26

but 7 isnt apart of any of my answer choices

Answer 27

u need to solve
x-5 =7
x-5 = -7

Answer 28

x= 12
x=-2

Answer 29

correct!

Answer 30

ok Solve the equation by completing the square: x2 - 8x + 15 = 0

Answer 31

same thing, here, the co-efficient of x is -8
divide it by 2, what u get ?

Answer 32

-4

Answer 33

yes, then square it...what u get ?

Answer 34

-16

Answer 35

-4 *-4 will be +16

Answer 36

oh

Answer 37

so, adding 16 on both sides...
\(x^2-8x+16=-15+16\)

Answer 38

right side:1
left side: idk

Answer 39

i think its x^2-4x-2x=1

Answer 40

is that right??????

Answer 41

@GoldPhenoix please help

Answer 42

\(x^2-8x+16 = (x-4)^2\)
so, we have
\((x-4)^2=1\)
just take square root on both sides!

Answer 43

?????????

Answer 44

when you take square root, the square part goes away!
(x+4) =+1 or x-4 =-1
find 2 values of x from here...

Answer 45

(x-3)(x+3) i think

Answer 46

a. x = + 5
b. x =-3 or x = 5
c. x =3 or x = -5
d. x =3 or x =5

Answer 47

x-4 = -1 , x = -1+4 = 3 is correct
but for 2nd part, you get
x-4 =1
x= 1+4 = 5

Answer 48

so, 3,5

Answer 49

oh yea

Answer 50

Solve the equation by completing the square: x^2 + 2x = 120

Answer 51

Do you know how to complete the square? :)

Answer 52

??????

Answer 53

I see. Here's an example:\[\Large x^2 + \color{red}6x =40 \]

Answer 54

What you do is take that coefficient (number beside) the x with NO EXPONENT. In our case, 6.

Answer 55

Take half of it, 3, and then square it, getting 9.

Answer 56

Now, add that to BOTH SIDES of the equation.
\[\Large x^2 +\color{red}6x\color{blue}{+9}=40\color{blue}{+9}\]

Answer 57

Simplify.
\[\Large x^2+\color{red}6x+9=49\]

Answer 58

You'll notice that the left side is now what you call a 'perfect square trinomial'
It may be expressed as...
\[\Large (x+\color{red}3)^2=49\]

Answer 59

Notice of course, that 3 is half of the original coefficient of x, which was 6.

Now take the square root of both sides:
\[\Large \sqrt{(x+3)^2}=\sqrt{49}\]
Notice that the square root and the square (exponent 2) cancel out.
But the square root of 49 may be either positive or negative 7.
\[\Large x+3=\pm7\]


Bring the 3 to the other side, you now get
\[\Large x = -3\pm7\]
which means either
x = -3 + 7 = 4
or
x = -3 - 7 = -10


Case Closed :)

Answer 60

So... go ahead now, get started with your own problem, using the same concepts.
I'll walk you through it if you like :)

Answer 61

yes please

Answer 62

By your lead :)

Answer 63

u on skype or call me at 803-937-6271 cus by u typing it it is confusing m please

Answer 64

I don't have skype.
come on, we can do this... I'll get you started...
\[\Large x^2 +\color{red}2x = 120\]

Answer 65

then call me i dont understand

Answer 66

@jessika96