To simplify the expression \( 5\sqrt{10} + \sqrt{10} \):
- Combine the like terms. We can factor out \(\sqrt{10}\):
\[ 5\sqrt{10} + 1\sqrt{10} = (5 + 1)\sqrt{10} = 6\sqrt{10}. \]
So, the simplified form of the expression is:
\[ 6\sqrt{10}. \]
From the responses you provided, the correct answer is:
6√10