√3 - √5

To simplify the expression √3 - √5, we cannot combine the square roots because they have different radicands (the numbers inside the square roots). However, we can leave it as it is or rationalize the denominator.

If we want to rationalize the denominator, we need to eliminate the square root from it. To do this, we can multiply both the numerator and denominator by the conjugate of the denominator, which means changing the sign of the second term. So, we multiply both the numerator and denominator by √5 + √3:

(√3 - √5)(√5 + √3) / (√5 + √3)

Using the distributive property, we can multiply it out:

= (√3 * √5) + (√3 * √3) - (√5 * √5) - (√5 * √3) = √15 + √9 - √25 - √15

Now, we can simplify further:

= √15 + 3 - √25 - √15 = 3 - √25

Since √25 = 5, the final simplified expression is:

= 3 - 5 = -2