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

The total cost is the original purchase cost plus 7% of that cost. Convert 7% to decimal form: $7\% = 0.07$.
The total cost $c$ equals the original cost $p$ plus $0.07p$, which simplifies to $c = p(1 + 0.07) = 1.07p$.

Step2: Identify independent variable

The independent variable is the input value that can change freely, which is the original purchase cost $p$.

Step3: Identify dependent variable

The dependent variable depends on the independent variable; here, total cost $c$ depends on $p$.

Answer:

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