Question 1182625
if she sell all {{{N=140}}} copies, we have
{{{P=20N+1800}}}
{{{P=20*140+1800}}}
{{{P=4600}}}

so, answer is:

description of values.........................................................set of values
domain: number of copies Rita has sold.........................{{{N=140}}} copies
range: Rita’s (total pay in dollars).............................{{{P}}}=${{{4600}}}