As a salesperson at Roaring Waves Beach Supplies, Carissa receives a monthly base pay plus commission on all that she sells. If she sells $500 worth of merchandise in one month, she is paid $405. If she sells $900 of merchandise in one month, she is paid $489.

Find Carissa's salary when she sells $1,700 worth of merchandise.

Question

As a salesperson at Roaring Waves Beach Supplies, Carissa receives a monthly base pay plus commission on all that she sells. If she sells $500 worth of merchandise in one month, she is paid $405. If she sells $900 of merchandise in one month, she is paid $489. 

Find Carissa's salary when she sells $1,700 worth of merchandise.

tkhunny · Answer

Formulas and thinking about it.

Pay = Base + Commission
Pay = Base + Sales*(Commission Rate)

Given information.

405 = Base + 500*(Commission Rate)
489 = Base + 900*(Commission Rate)

Solve for missing components.