Question

Solve the radical equation
√(x+4) +√(x-4)=4

Answer 1

I don't know where to begin...can I square everything? to get rid of the square roots, that is.

Answer 2

√(x+4)=4 -√(x-4)
x+4=x-8√(x-4)+12
4=-8√(x-4)+12

Answer 3

think you can solve it from there

Answer 4

I am confused....why did you do what you just did?

Answer 5

subtract √(x-4) from both sides

Answer 6

square both sides

Answer 7

simplify

Answer 8

I understand. but why did you have to subtract the √(x-4) from both sides?
can't we just square everything and combine like terms, isolate x and that is our answer?

Answer 9

well, if you square both sides, you get 2x+√(x+4)√(x-4)=16, which looks a lot more complicated

Answer 10

I mean 2x+2√(x+4)√(x-4)=16

Answer 11

no...you would get:
(√(x+4))^2 +(√(x-4))^2=(4)^2
x+4 +x-4=16
which is 2x=16
x=8

Answer 12

that is my logic anyway

Answer 13

no, you gotta square everything

Answer 14

but I did

Answer 15

(√(x+4) +√(x-4))^2=(4)^2

Answer 16

the square gets rid of the square rooots

Answer 17

(√(x+4) +√(x-4))(√(x+4) +√(x-4))=16

Answer 18

oh

Answer 19

(√(x+4) +√(x-4))(√(x+4) +√(x-4)) does not equal (√(x+4))^2 +(√(x-4))^2

Answer 20

that is irritating... -_-
so either way, I am going to have to foil....?

Answer 21

yep

Answer 22

meh :(
well, thanks for your help

Answer 23

np