Question

Solve the equation by completing the square. If necessary, round to the nearest hundredth.

x² – 18x = 19
1; 19
–1; 19
3; 6
–3; 1

Could someone help me with this? Thanks in advance.

Answer 1

What does that last pic say?

Answer 2

who needs ... square?!

Answer 3

thanks though :D

Answer 4

What do you think @Dharmaputra_993?

Answer 5

I was typing the answer, but Luis is helping you so it's okay :)

Answer 6

Okay, Thanks for trying ;D

Answer 7

@Luis_Rivera Wouldnt it be
\[(x + 1)(x - 19) = 0\]

Answer 8

Can you explain you reasoning?

Answer 9

x^2 - 18x = 19

x^2 - 18x - 19 = 0

Find two numbers that multiply to -19 and add to -18...those two numbers are 1 and -19, so x^2 - 18x - 19 factors to (x+1)(x-19)

x^2 - 18x - 19 = 0

(x+1)(x-19) = 0

x+1 = 0 or x-19 = 0 ... use the zero product property here

x = -1 or x = 19

Answer 10

Can you explain your* reasoning?

Answer 11

@some_someone ?

Answer 12

\[x² – 18x = 19\]
\[x² – 18x + 81= 100\]
\[(x - 9)^2 = 100\]
\[x - 9 = 10 \]
\[x = 19\]
\[x - 9 = -10 \]
\[x = -1\]

Answer 13

Well, it can't be 19...

Answer 14

Oops...

Answer 15

Lol brain fart :)P

Answer 16

@jim_thompson5910 so i was right?
and @FlashMobRiot it would be –1; 19

Answer 17

Sorr, I'm multitasking :)

Answer 18

its okaii :)

Answer 19

Yup, you and @Luis_Rivera and @jim_thompson5910 were all right :D

Answer 20

yeah the solutions to x^2 - 18x = 19 are x = -1 or x = 19

Answer 21

Luis_Rivera was close, but he had his signs backward

Answer 22

I can't give you all best response...so try to be as unbiased as you can, who should get it?

Answer 23

I think @some_someone maybe should get it because he has the lowest number compared to @jim_thompson5910

Answer 24

Is that ok? @jim_thompson5910 ?

Answer 25

go for it, i don't mind

Answer 26

Ok thanks :)P

Answer 27

as long as i helped, that's all i care about really

Answer 28

Yup you definetly did

Answer 29

I'm glad I did

Answer 30

I have one other question I'm a bit skeptical about, do you mind checking it out? If so here it is:
Solve. x² – 81 = 0
1) 0
2) –9
*3) –9, 9
4) 9
(Hint: * means the one I chose)

Answer 31

you got it

Answer 32

if you're not sure, just plug in the possible solutions back in for x

Answer 33

Ok thanks for looking it over

Answer 34

Oh Ok

Answer 35

then evaluate and simplify and you should get 0 = 0, which is a true equation

Answer 36

Yea...I do that alot on my state test lol. Well thanks have a great day, and bye :D

Answer 37

Once @some_someone is done typing I'll close the question.

Answer 38

that's good to know

checking your answer is always a good idea

yw, cya later

Answer 39

Thanks, Bye everyone I'm logging out.