## anonymous one year ago can someone help me with simplifying radical expressions? 1/sqrt(x)+sqrt(y)

1. anonymous

|dw:1440999970186:dw|

|dw:1441000576022:dw|

3. jim_thompson5910

multiply top and bottom by $\Large \sqrt{x}-\sqrt{y}$ |dw:1441000755361:dw|

4. jim_thompson5910

why do this? because you will take advantage of the fact that (a-b)(a+b) = a^2 - b^2 squaring the square root will cancel out the square root eg: $\Large (\sqrt{x})^2 = x$ where is nonnegative

so where did i go wrong

6. jim_thompson5910

you didn't make a mistake @madhu.mukherjee.946 $\Large \frac{1}{\sqrt{x}+\sqrt{y}} = \frac{\sqrt{x}-\sqrt{y}}{x-y}$ is true assuming $$\Large x \ne y$$ and neither x nor y are zero

thanks

so @Mando98 your sum is solved

9. anonymous

so the final answer is |dw:1441001112100:dw|

10. jim_thompson5910

yes

11. anonymous

thank you and do you think you could help me out with 2 more problems (similar to this one)?

12. jim_thompson5910

sure just post them as separate posts to avoid clutter