How do you combine sqrt18-sqrt8?

Oct 21, 2015

$\sqrt{2}$

Explanation:

$\sqrt{18} - \sqrt{8}$........................(1)

Write $\sqrt{18} \text{ }$ as $\sqrt{2 \times 9} = 3 \sqrt{2}$.......(2)

Write $\sqrt{8} \text{ }$ as $\sqrt{2 \times 4} = 2 \sqrt{2}$.........(3)

Substitute (2) and (3) into (1) giving:

$3 \sqrt{2} - 2 \sqrt{2}$

3 of something minus 2 of the same thing gives just one of the thing

So $\text{ "3sqrt(2)-2sqrt(2)" " = " } \sqrt{2}$