2/ 4+ radical 5x

Question

2/ 4+ radical 5x

anonymous · Answer

$$2\div4+\sqrt{5x}$$

anonymous · Answer

So when I begin, I multiply the equation by 5x/5x. and end up with 10x/4+5x...

Than when I reduce, I get 1/2 - how close am I?

hero · Answer

$$\frac{2}{4+\sqrt{5x}}$$

anonymous · Answer

yes that is the original equation

hero · Answer

Well, the problem is, it's 4 + sqrt{5x} so you can't just multiply top and bottom by sqrt{5x}

anonymous · Answer

why not?  isn't that what we did on the last one?

hero · Answer

You have to multiply top and bottom by 4 - sqrt{5x}, which is the conjugate

hero · Answer

The last one we did was 5 times sqrt{3}, not plus

anonymous · Answer

Oh!
Let me try this one for a second, and see how I do please

anonymous · Answer

how about 2/11?

anonymous · Answer

anybody?

phi · Answer

you have to multiply the top and bottom by the conjugate, so you should have a square root in the numerator.

phi · Answer

All you can do with this problem is move the square root from the denominator, but it ends up in the numerator.   The only reason people do this, is they hate square roots in the bottom.

anonymous · Answer

so the numerator would be 8 - 2$$\sqrt{5x}$$

anonymous · Answer

the square root should be right after the 2, just having technical issues.

phi · Answer

yep, assuming that is all on one line. and what did you get for the bottom?

anonymous · Answer

11

phi · Answer

well today is sept 11.

anonymous · Answer

no - that should be 16 - 5x instead!

phi · Answer

much better

anonymous · Answer

Thank you!  I have another one - I will post on the other side - please look for it!  I am so frustrated with these darn radical signs!