complete the square ? x2 + 8x = 11

- anonymous

complete the square ? x2 + 8x = 11

- Stacey Warren - Expert brainly.com

Hey! We 've verified this expert answer for you, click below to unlock the details :)

- katieb

I got my questions answered at brainly.com in under 10 minutes. Go to brainly.com now for free help!

- anonymous

What would you add to both sides?

- anonymous

idk , 8

- anonymous

You take half of the x term so half of 8 = 4
Then you square that answer 4^2 = 16

Looking for something else?

Not the answer you are looking for? Search for more explanations.

## More answers

- anonymous

do you know what the x term refers to?

- anonymous

no how many times do i have to say math is thee worse subject i dont know how to do this

- anonymous

the x term refers to the number in front of the x

- anonymous

you are asked to make the given equation into a square.

- anonymous

x^2+8x-11 = 0

- anonymous

do you know what the formula for (a+b)^2 is?

- anonymous

in other words,
\[(a+b)^{2} = ?\]

- anonymous

no

- anonymous

okay,
\[(a+b)^{2} = a ^{2}+ 2ab +b ^{2}\]

- anonymous

so the example that i just put up how would that work

- anonymous

compare \[x ^{2}+8x - 11.\]
and
\[a ^{2}+2ab+b ^{2}\]

- anonymous

x is a. 2ab is 8x

- anonymous

so what must you add to -11 to make it into b^2?

- anonymous

2ab

- anonymous

okay try again.
when you compare the two equations, you see that x = a. correct?
and 2ab = 8x.
so find the value of b.

- anonymous

which grade are you in?

- anonymous

idk , im srry im not Tht qood in math

- anonymous

okay,
2ab = 8x, divide by 2a on both sides.
=> b = 8x/2a
you know that x = a
so what is the value of b?

- anonymous

16 , i did 8*2 16

- anonymous

i mean 4 ,

- anonymous

okay good.

- anonymous

thats riqqht

- anonymous

so for (a+b)^2 to be equal to (x+4)^2, what must you add to x^2 +8x-11?

- anonymous

expand (x+4)^2.

- anonymous

maybe 2 0r 4 because i did 8\[\div\]2 qive me 4 then i square root that and qave me 2.

- anonymous

what? you found out that x = a and 4 = b. so your complete square is (x+4)^2.
so expand (x+4)^2 using the formula i gave earlier.

- anonymous

okay \[(x+4)^{2}= x ^{2}+8x+16\]

- anonymous

im in the 12th .

- anonymous

you are in 12th grade and don't know what (a+b)^2 is ?That is very surprising. Anyway,
compare the expanded version of (x+4)^2 i gave you with your original formula, x2+8x-11

- anonymous

how much do you need to add to x2+8x-11 to get x2+8x+16?

- anonymous

itss not because to mee math is hard for one and for two yu dont have to help mee someone else can if its like that im on here for help not for someone to tell im in the 12th i dont know what something is i guess maybe it dont get through to mee to many smart retricepeople wrong thing for me to come to flutter .

- anonymous

im dont off this question anyway .

- anonymous

make some sense. I did not want to offend you. I was just surprised. I thought basic algebra was taught in 8th grade or something.

- anonymous

you know what flutter you and your negative attititude if yu aint going to help go some where with you ignorgant self and it probably was and wht its 2011 not 2007

- anonymous

okay, have a pleasant day.

- anonymous

you to , feather ! *

- anonymous

Ah, well at least I'm not stupid.

Looking for something else?

Not the answer you are looking for? Search for more explanations.