Question

√9x+81=x+5

Answer 1

What would you do?

Answer 2

subtract 5 from both sides

Answer 3

good

Answer 4

\[\sqrt{9} x+76=x\]

Answer 5

what's next?

Answer 6

looks hard

Answer 7

yeah I am confused from that point.

Answer 8

well if you knew to subtract 5...why not subtract 76 now?

Answer 9

√9x=x

Answer 10

from both sides

Answer 11

but I think that is wrong.

Answer 12

√9x = x - 76.....now how do you get rid of square roots?

Answer 13

lost again.

Answer 14

okay...u subtracted 5 from both sides correct?

Answer 15

yeah i did that.

Answer 16

okay...now you want to get the square root alone...so you need to subtract 76 from both sides...

Answer 17

so your going from √9x + 76 = x and when you subtract 76 from both sides...your left with √9x = x -76

Answer 18

now what do we do about this square root?

Answer 19

1/2(161+3√313) that is what I keep getting.

Answer 20

okay...well lets slow down...

Answer 21

do you know how to remove the square root?

Answer 22

nope

Answer 23

okay...when you have addition...you subtract from both side right?

Answer 24

right

Answer 25

so when you have a square root....you square both sides

Answer 26

okay

Answer 27

so now that we square both sides...we get 9x = (x-76)^2

Answer 28

I have 20 minutes to get this done.

Answer 29

what next?

Answer 30

i am going to make a guess that this is
\[\sqrt{9x+81}=x+5\] am i right?

Answer 31

that is the right problem

Answer 32

thougth so nice integer solution
square both sides as stop one

Answer 33

get \[9x+81=(x+5)^2\]

Answer 34

right

Answer 35

then expand and get
\[9x+81=x^2+10x+25\]

Answer 36

right

Answer 37

okay...the way you wrote the question dude....i didn't realize the 81 was under the square root

Answer 38

but follow satellite...he won't steer you wrong

Answer 39

let me re write it

Answer 40

put all terms on one side of equation and solve the quadratic
\[x^2+x-56=0\]

Answer 41

\[\sqrt{9x+81}=x+5\]

Answer 42

factor and solve, then check your answer

Answer 43

-8 and 7 is what I am getting

Answer 44

other way around

Answer 45

still saying it is wrong. I am so lost.

Answer 46

cause u got your answers backwards....its 8 and -7

Answer 47

you are not done yet

Answer 48

you have to check the answers in original equation

Answer 49

I did it both ways and it said i was wrong

Answer 50

now you have to check your answers as satellite is saying

Answer 51

check your answers in
\[\sqrt{9x+81}=x+5\]

Answer 52

-7 will not work

Answer 53

is 8 the answer

Answer 54

reason being that step one was square, so you introduced and extraneous root

Answer 55

I checked it and it is not coming out right

Answer 56

I only have 15 minutes left

Answer 57

solution is 7