math
posted by nick .
in the question 6radical x +3 radical y 2radical y +3 radical x radical y is the answer 9 radical x +1 radical y. i just don't get it thanks

6√x + 3√y  2√y + 3√x  √y
= 9√x
(6apples + 3 oranges  2 oranges + 3 apples  1 orange
= 9 apples)