Answer:
a x sqrt(7) - 49sqrt(x)
Explanation:
sqrt(7x) [ sqrt(x) - 7sqrt(7)]
Distribute
sqrt(7x) *sqrt(x) - sqrt(7x)*7sqrt(7)
We know that sqrt(a) sqrt(b)= sqrt(ab)
sqrt(7x^2) - 7sqrt(7^2 *x)
Now lets separate out the perfect squares
sqrt(7) *sqrt(x^2) - 7sqrt(7^2)*sqrt(x)
x sqrt(7) - 7*7sqrt(x)
x sqrt(7) - 49sqrt(x)