Use the associative property of addition and the distributive property to justify that a(b+c+d) = ab +ac+ad

Help?
I don't know what it's asking..

2 answers

The distributive property means you DISTRIBUTE a number/variable to other numbers in a set of parentheses. So, in this example, you would distribute a to b, c, and d to get this:

a => b
a => c
a => d

ab + ac + ad
But how do I justify my answer/use associative property?