9√'14-8√'14

To simplify this expression, we can combine like terms.

First, let's simplify the square roots:

√14 = √(2 * 7) = √2 * √7

Now we can rewrite the expression as:

9√2 * √7 - 8√2 * √7

The square root terms (√2 * √7) are the same, so we can combine the coefficients:

(9 - 8)√2 * √7

Simplifying further, we have:

1√2 * √7

Finally, we can rewrite the square root term as:

√(2 * 7) = √14

Therefore, the simplified expression is:

√14