Final answer:
All options provided (1) y = mx + b, 2) y = x², 3) y = 2x + 3, and 4) y = 3x - 2) represent y as a function of x, with options 1), 3), and 4) being linear equations and option 2) being a quadratic equation.
Step-by-step explanation:
The question asks which representation shows y as a function of x. A function represents a relationship where every value of x has a unique value of y. All of the given choices represent functions because for each x value there is only one corresponding y value.
Practice Test 4 Solutions for Linear Equations
Options 1), 3), and 4) are in the standard form y = mx + b, where m represents the slope and b represents the y-intercept of a straight line on a graph. This is a linear equation. Option 2) shows a quadratic equation, y = x², which also depicts y as a function of x, but the graph of this function is a parabola, not a straight line.
Here, the term m signifies the slope, and b signifies the y-intercept. For instance, in the equations y = 9 + 3x and y = 3x - 2, 3 is the slope and 9 and -2 are the y-intercepts, respectively.