Question 7

(Multiple Choice Worth 2 Points)
(Graphing Linear Equations MC)

Which graph represents the equation y equals one half times x plus 2?
graph of a line passing through the points negative 2 comma negative 2 and 0 comma negative 1
graph of a line passing through the points negative 2 comma 0 and 0 comma 1
graph of a line passing through the points negative 2 comma negative 3 and 0 comma negative 2
graph of a line passing through the points negative 4 comma 0 and 0 comma 2

1 answer

To determine which graph represents the equation \( y = \frac{1}{2}x + 2 \), we can evaluate the y-intercept and the slope of the line.

  1. Y-intercept: The y-intercept occurs when \( x = 0 \).

    • Plugging \( x = 0 \) into the equation: \[ y = \frac{1}{2}(0) + 2 = 2 \] This tells us that the line intersects the y-axis at the point (0, 2).
  2. Slope: The slope of the line is \( \frac{1}{2} \), which means that for every increase of 1 in \( x \), \( y \) increases by \(\frac{1}{2}\).

Now, let's analyze the options given:

  1. Graph of a line passing through the points (-2, -2) and (0, -1):

    • At \( x = 0 \), \( y \) is -1, which does not match our y-intercept of 2.
  2. Graph of a line passing through the points (-2, 0) and (0, 1):

    • At \( x = 0 \), \( y = 1\), which does not match our y-intercept of 2.
  3. Graph of a line passing through the points (-2, -3) and (0, -2):

    • At \( x = 0 \), \( y = -2\), which does not match our y-intercept of 2.
  4. Graph of a line passing through the points (-4, 0) and (0, 2):

    • At \( x = 0 \), \( y = 2\), which matches our y-intercept.
    • The slope can also be checked; from (-4, 0) to (0, 2):
      • Change in y = \( 2 - 0 = 2\)
      • Change in x = \( 0 - (-4) = 4\)
      • Slope = \( \frac{2}{4} = \frac{1}{2} \)

Thus, the correct answer is:

Graph of a line passing through the points (-4, 0) and (0, 2).