How do you solve a distributive equation

Let's say you are given the equation 4 (x+5). What you must do is distribute the 4 to everything inside the parenthesis. What this means is that you multiply everything inside the parenthesis by the number outside the parenthesis (in this equation that would be 4). For example, the equation 4 (x+5) would distribute as (4*x) + (4*5). This would then become 4x+20.