Question

Please help.. solve quadratic equation by completing square..

Answer 1

Just need some one to explain ..... -x^2+6+10 =0 ... i moved the 10 the LHS

Answer 2

but i dont know what to do from there

Answer 3

is it 6x?

Answer 4

this doesn't need to solve by completing square??!!

Answer 5

yes

Answer 6

@CalebBeavers

Answer 7

Well first pull out the -1

-x^2+6x+10=0
-(x^2-6x-10)=0

now take the coefficient of x , divide it by 2 and then square that number, what do you get?

Answer 8

9??

Answer 9

Yep, now add and subract that number after x like this

-(x^2-6x+9-9-10)=0

now factor the first part (x^2-6x+9)

Answer 10

what do i do with the -9 and - 10

Answer 11

@CalebBeavers

Answer 12

Just subtract them, but first how did the first part factor?

Answer 13

I dont know what that means -_-

Answer 14

You've never done factoring?

Answer 15

mmmm like this right

Example: factor 2y+6

Both 2y and 6 have a common factor of 2:
•2y is 2 × y
•6 is 2 × 3

Answer 16

@CalebBeavers

Answer 17

like that yea

but can you factor x^2-6x+9?

Answer 18

x^2-6x+9 = (x - 3)(x - 3) -- @CalebBeavers

Answer 19

Right, or (x-3)^2

so now we have

-((x-3)^2-19)=0

redistribute the -1

-(x-3)^2+19=0

now move the 19 to the right

Answer 20

-(x-3)^2=19

Answer 21

its being added to the left side so you subtract it

-(x-3)^2=-19

Answer 22

now, divide both sides by -1

Answer 23

3^2=19?

Answer 24

where did the x go?

the whole left side is being multiplied by -1 so

(x-3)^2=-19/-1
(x-3)^2=19

take square root of both sides now

Answer 25

Oh geez im stupid ................. uh . do you mean like SR of 3 and 19 ?

Answer 26

@CalebBeavers

Answer 27

Square root, it just eliminates the squaring on the left so you have

\[x-3=\pm \sqrt{19}\]

Answer 28

now just add 3 to both sides =D

Answer 29

YOUR THE BESTEST @CalebBeavers

Answer 30

x-3=4.358898943540674
X-6=7..358898943540674
{{{ I THINK I MESSED UP}}}

Answer 31

@CalebBeavers

Answer 32

Where did that even come from

Answer 33

i have no clue

Answer 34

add 3 to both sides...

\[x=3 \pm \sqrt{19}\]

gives two equations

\[x=3+\sqrt{19}\]

and
\[x=3-\sqrt{19}\]

Answer 35

ohh .... i squared rooted 19 -_- but i get it noww THANKS....