To distribute something means to divide / share a part of something. The distributive property works similarly. The distributive property states that multiplying the total sum of two variables by a number is the same as the total sum of each product of individual variables and the number.
For example: a(b+c) = ab + ac
Therefore, in order to distribute the 13 into the terms inside the parentheses, you follow the distributive property and multiply each individual variable in the parentheses by 13 and add all the resulting products.
