# Thread: [SOLVED] Surds...express with rational denominator

1. ## [SOLVED] Surds...express with rational denominator

The question is-
4 √3 - 2 √2
7
√5

2. Originally Posted by salam
The question is-
4 √3 - 2 √2
7 √5
$
\frac{4(\sqrt{3}-2\sqrt{2})}{7\sqrt{5}}
$

Multiply numerator and denominator with $\sqrt{5}$
So the value becomes

$
=\frac{4\sqrt{5}(\sqrt{3}-2\sqrt{2})}{7(\sqrt{5})^2}

$

$
=\frac{4(\sqrt{5\times 3}-2\sqrt{2\times 5})}{35}
$

$
=\frac{4(\sqrt{15}-2\sqrt{10})}{35}
$

Now one more thing, you will find it really better if you learn Latex

3. Sorry for just posting it up
i have the answer but i wanna know if the denominator can be simplified caz i got a different denominator to the answer in mu booklet answer.
My denominator i got was 7 and the book has it as 35. plzz help

4. thankss alott
i get how u did it and thanks again and ill surely learn latex ..