Rationalize the denominator and simplify: sqrt a/8- sqrt a

To rationalize the denominator and simplify the expression sqrt(a)/8 - sqrt(a), we need to get rid of the square root in the denominator.

First, let's rewrite the expression as:

sqrt(a) / 8 - sqrt(a) = sqrt(a) / 8 - 8 * sqrt(a) / 8

Next, to combine the terms, we need a common denominator. In this case, the common denominator is 8. Therefore, we can rewrite the expression as:

(sqrt(a) - 8 * sqrt(a)) / 8

Now, combine the terms in the numerator:

(sqrt(a) - 8 * sqrt(a)) = (1 - 8)sqrt(a) = -7sqrt(a)

So, putting it all together, the simplified and rationalized expression is:

-7sqrt(a) / 8