Answer
$15a+5b+45c$
Work Step by Step
To find a product using the distributive property, you take the coefficent--in this case the 5 outside of the parentheses--and multiply it by each term within the parentheses separately.
The first term within the parentheses is $3a$, so the first term of the product is $5\times3a$, or $15a$.
The second term within the parentheses is $b$, so the second term of the product is $5\times b$, or $5b$.
The third term within the parentheses is $9c$, so the third term of the product is $5\times 9c$, or $45c$.
The terms within the parentheses are connected by plus signs, so the terms within the product will be too.
The final product after distributing the 5, therefore, is $15a+5b+45c$.
