Question 1090037
The first compact disc cost $15.95 - that's given.  The rest cost $3.99 each.  If the customer bought a total of 6 compact discs, then we know that they bought 5 compact discs at the $3.99 each price.  So we need to add up $3.99 5 times to figure out how much was paid.  An easier way to do this is with multiplication.
{{{5*3.99 = 19.95}}}
So the customer paid $15.95 for the first compact disc, and $19.95 for the remaining 5.  To find out the total cost we add.
{{{15.95 + 19.95 = 35.90}}}
So the customer paid $35.90 for the 6 compact discs.