Thread: Help with rationalizing expressions

1. Help with rationalizing expressions

I need help with a couple of rationalization questions. I am totally confused.

square root 5x minus 6 / squareroot 5x plus 3

(squareroot 2+y plus squareroot 2-y)/y

2. Originally Posted by shiel8
I need help with a couple of rationalization questions. I am totally confused.

square root 5x minus 6 / squareroot 5x plus 3

(squareroot 2+y plus squareroot 2-y)/y
Is it

(1) $\displaystyle \frac{\sqrt{5x-6}}{\sqrt{5x+3}}$ ?

or

(2) $\displaystyle \frac{\sqrt{5x}-6}{\sqrt{5x}+3}$

Also group what's under the radical in your second problem as well.

3. for the second questions it's 2+y under squareroot symbol minus 2-y under squareroot symbol all over y

how do you enter info in the format you're using? It'd be much easier to post if I knew how to do that.

4. Originally Posted by shiel8

for the second questions it's 2+y under squareroot symbol minus 2-y under squareroot symbol all over y

how do you enter info in the format you're using? It'd be much easier to post if I knew how to do that.

Have a look here: http://www.mathhelpforum.com/math-he...-tutorial.html
Use a factor such that you get a sum of squares in the denominator:

$\displaystyle \dfrac{\sqrt{5x} - 6}{\sqrt{5x} + 3}=\dfrac{\sqrt{5x} - 6}{\sqrt{5x} + 3} \cdot \dfrac{\sqrt{5x} - 3}{\sqrt{5x} - 3}= \dfrac{5x-9\sqrt{5x} +18}{5x-9}$

5. Thanks Earboth.

Hopefully this works right. The other question I need help with is:

$\displaystyle \frac{\sqrt{2+y} + \sqrt{2-y}}{y}$