#### Answer

$3x+15$

#### Work Step by Step

To find a product using the distributive property, you take the coefficent--in this case the 3 outside of the parentheses--and multiply it by each term within the parentheses separately.
The first term within the parentheses is $x$, so the first term of the product is $3\times x$, or $3x$.
The second term within the parentheses is $5$, so the second term of the product is $3\times5$, or $15$.
The terms within the parentheses are connected by a plus sign, so the terms within the product will be too.
The final product, therefore, is $3x+15$.