-6 - radical 10 / 3+8 radical 10

type it this way:

(-6 - √10)/(3 + 8√10)

I will assume you are rationalizing

(-6 - √10)/(3 + 8√10)
= (-6 - √10)/(3 + 8√10) * (3 - 8√10)/(3 - 8√10)
= (-18 + 48√10 - 3√10 + 80)/(9 - 640)
= ( 62 + 45√10)/-631
= (-62 - 45√10)/631