(√48+√3) •√3

To simplify \((\sqrt{48} + \sqrt{3}) \cdot \sqrt{3}\), you can distribute \(\sqrt{3}\) to both terms inside the parentheses:

\[ (\sqrt{48} + \sqrt{3}) \cdot \sqrt{3} = \sqrt{48} \cdot \sqrt{3} + \sqrt{3} \cdot \sqrt{3} \]

Now, simplify each term:

1. For \(\sqrt{48} \cdot \sqrt{3}\): \[ \sqrt{48 \cdot 3} = \sqrt{144} = 12 \]

2. For \(\sqrt{3} \cdot \sqrt{3}\): \[ \sqrt{3} \cdot \sqrt{3} = 3 \]

Now combine the results: \[ 12 + 3 = 15 \]

So, the final result is: \[ (\sqrt{48} + \sqrt{3}) \cdot \sqrt{3} = 15 \]