Answer:
Step-by-step explanation: To simplify this problem, we must get rid of the radical on the square root of 6 in the denominator and to do that, we multiply top and bottom of the fraction by the square root of 6.
Notice that in the numerator, we must distribute
the square root of 6 through the 6√7.
So we get 6√42 / √36.
Since the square root of 42 is already simplified,
we can simply the square root of 36 on the bottom to get 6.
So we have 6√42 / 6.
Now the 6's outside the radical both cancel leaving us with √42.
My work is attached in the image provided.