Question

(3x-3)^(1/2) + (7x+8)^(1/2)=(17x +13)^(1/2)

Answer 1

square both sides..
keep (something)^1/2 on 1 side and the rest on the other..
square again
you should come up with a quadratic eqn..

Answer 2

Power half indicates square root. ^_^

\[\sqrt{3x-3}+\sqrt{7x+8}=\sqrt{17x+13}\]
\[\sqrt{3x-3}^2+\sqrt{7x+8}^2=\sqrt{17x+13}^2\]
\[3x-3+7x+8=17x+13\]
10x+5=17x+13
-7x+8
x=-8/7

Answer 3

@chaise what are you doing!!

Answer 4

:O

Answer 5

x^(1/2) = sqrt(x)

x=sqrt(x)^2.

What you do to one side of the equation, make sure you do to the other.

Answer 6

just check your second step!! note that (a+b)^2 is not a^2 + b^2

Answer 7

square root and power half cancel eachother out. I have no idea what you are on about. My answer is correct, as far as I'm aware.

Answer 8

(3x-3)^(1/2) + (7x+8)^(1/2)=(17x +13)^(1/2)
when you sq both sides you have
3x -3 + 7x + 8 + 2 sqrt [(3x-3)(7x+8)] = 17 x +13
which is quite different from what you wrote..

Answer 9

-8/7 cant be the ans...its out of domain of sqrt(3x-3) !!

Answer 10

altough am too lazy solving,,but i now what i say is correct here..

Answer 11

@chaise hope its clear? i mean i maybe wrong (no chance here :P )..but correct me in that case..

Answer 12

http://www.wolframalpha.com/input/?i=%283x-3%29%5E%281%2F2%29+%2B+%287x%2B8%29%5E%281%2F2%29%3D%2817x+%2B13%29%5E%281%2F2%29

Answer 13

So, square (3x-3) + (7x+8)^1/2 = 17x+13?
Then square again? (3x-3) + (7x+8) = (17x+13)^2?

Answer 14

@chaise i'll tell you whats happening here..
x=-8/7 will give a complex solution,,i dont think its the required case here
and your method yields -8/7 because in sqrt(7x +8) , x=-8/7 makes it 0..so
2sqrt[(3x-3)(7x-8)]=0 ,,thus even your mistake yielded a complex root..
what about the only real solution? does your method provide that?
mind you,,its not gonna work every time..

Answer 15

@jazzylj i'll use this
let 3x- 3=a ,, 7x - 8 =b and 17x + 13 =c
so you have sqrt(a) + sqrt(b) = sqrt(c)
on squaring,,you get
a + b + 2sqrt(ab) = c
=> 2 sqrt(ab) = c-a-b
now square both sides..
4ab = something
this is how you'll have to do..