Question

(Sqrt(x-4)+1) = sqrt(x+9)

Answer 1

\[\LARGE \sqrt{x-4}+1=\sqrt{x+9}\]
squaring both sides we have:
\[\LARGE (\sqrt{x-4}+1)^2=(\sqrt{x+9})^2\]
now use this formula:
\[\LARGE (a+b)^2=a^2+2ab+b^2 \]
for the left side... and for the right side just cancel out square root with square

Answer 2

so would it be x^2-8+1=x+9

Answer 3

no , try again.

Answer 4

or show what have you done , so we can correct you.

Answer 5

i tried to use the formula for the left side

Answer 6

can I see how did you use it?

Answer 7

i was just trying to see if thats how it would come out when u plug the numbers in for a b and c in the formulat

Answer 8

there's no C ... I'll ask you again. Can I see how did you use it?

Answer 9

\[x^2+2(1)(-4)+1^2\]

Answer 10

\[\Large (\sqrt{x-4}+1)^2=(\sqrt{x-4})^2+2\cdot[ 1\cdot \sqrt{x-4}]+1^2 \]

Answer 11

ok i see what i did wrong but now what do you do with all of this?

Answer 12

to simplify ...
\[\LARGE (\sqrt{x-4})^2+2\sqrt{x-4}+1=\]
\[\LARGE x-4+1+2\sqrt{x-4 }=\]
\[\LARGE x-3+2\sqrt{x-4}\]
so your equation would look like:
\[\LARGE x-3+2\sqrt{x-4}=x+9 \]
... what can we do now? :)

Answer 13

cancel the x's and subtract the -3?

Answer 14

yes...
\[\LARGE 2\sqrt{x-4}=9+3 \]
\[\LARGE 2\sqrt{x-4}=12 \]
what can we do now?

Answer 15

im not exactly sure..... do you have to square it?

Answer 16

not actually :) (we can do it now, but it just would give us bigger numbers)
we want to simplify it a bit :)
let's divide both sides by 2
and we get?

Answer 17

sqrt(x-4) =6

Answer 18

well done...
now we square both sides.
and we get?

Answer 19

x-4=36

Answer 20

x=40

Answer 21

That's correct. Well done . ;)

Answer 22

thank you