Surds -- Help Please

Express (√8+√50)/√490 as a simple surd fraction with a rational denominator.

I have got this to 7√2 / 7√10 and do not know how to get a rational denominator from a surd.

(sqrt(8) + sqrt(50)) / sqrt(490)
(sqrt(2^2 * 2) + sqrt(5^2 * 2)) / sqrt(7^2 * 10)
(2 * sqrt(2) + 5 * sqrt(2)) / 7 * sqrt(10)
7 * sqrt(2) / 7 * sqrt(10)
sqrt(2) / sqrt(10)
sqrt(2 / 10)
sqrt(1 / 5)
1 / sqrt(5)
(sqrt(5) / sqrt(5)) * (1 / sqrt(5))
sqrt(5) / 5

=√2/√10=1/√5=√5/5

nm