Question

1. the total cost, c, after a sales tax of 7% is applied to the cost of a purchase, p.

equation:
independent variable:
dependent variable:

Explanation:

Step1: Define total cost formula

A 7% sales tax means the total cost is the purchase price plus 7% of the purchase price. This can be written as:
$c = p + 0.07p$

Step2: Simplify the equation

Combine like terms for the purchase price:
$c = 1.07p$

Step3: Identify independent variable

The independent variable is the value that is set freely, which is the purchase cost $p$.

Step4: Identify dependent variable

The dependent variable is the value that depends on the independent variable, which is the total cost $c$.

Answer:

Equation: $c = 1.07p$
Independent variable: $p$ (the cost of a purchase)
Dependent variable: $c$ (the total cost after sales tax)