17) a toy-store salespersons is paid a daily salary plus commission. when her sales are $200, she
earns $115 per day. when her sales are $400, she earns $155.
a) write the equation that models the situation. be sure to define the variables you use.
b) what is their daily salary?
c) what percent commission does she earn?
d) how much would she earn if her sales were $500?
e) how much does she need to sell to earn $500 for the day?