Final answer:
A graph is an illustration of the set of points whose ordered pairs (x, y) are solutions to an equation, showing the relationship between an independent and a dependent variable on a two-dimensional plot. All the given options represent linear equations since they fit the y = mx + b format.
Step-by-step explanation:
A graph of an equation is an illustration of the set of points whose ordered pairs are solutions to the equation. When we plot a graph, we use values of the independent variable (x) to determine the corresponding values of the dependent variable (y), and each pair (x, y) represents a solution to the equation.
The relationship between the two variables is shown on a two-dimensional plot with the independent variable on the horizontal axis and the dependent variable on the vertical axis. Graphs are key tools, especially when dealing with linear equations, as they provide a visual representation of the relationship between variables.
Linear equations are of the form y = mx + b, where 'm' is the slope and 'b' is the y-intercept. All the options A) y = -3x, B) y = 0.2 + 0.74x, and C) y = -9.4 - 2x given in Practice Test 4 are examples of linear equations because they can be written in this form.