Corinne has a job selling magazines. She earns $7.50 per hour plus 20% of the total amount of her sales. She also gets an allowance of $40 per week for gas. She knows her weekly earnings can be shown using the following expression:

7.50h + 0.20s + 40

Part A: Identify a coefficient, a variable, and a constant in this expression. (3 points)

Part B: If Corinne works for 25 hours and sells $300 in magazines, how much does she earn for the week? Show your work to receive full credit. (4 points)

Part C: If Corinne gets a raise and begins earning $9 per hour, would the coefficient, variable, or constant in the equation change?

Respuesta :

A. variable is an unknown number substituted in by a letter, such as h or s
    coefficient is the number multiplied by the variable.....7n....coefficient is 7
    constant is just a number with no variables attached.
    7.50h + 0.20s + 40.....coefficient is 7.50 or 0.20....variable is h or         s....constant is 40

B. 7.50h + 0.20s + 40 = her pay for the week
     she works 25 hrs....so sub in 25 for h....she sells 300....so sub in 300 for      s. ---- 7.50(25) + 0.20(300) + 40 = 287.50 <== her weekly pay

C. if she made 9 per hr instead of 7.50, the coefficient would change.
     It would be 9.00h + 0.20s + 40