Identify the Linear Equation with a Slope of -1 from the Graph

Question

Which of the following equations corresponds to the function represented in the graph?

–8–8–8–7–7–7–6–6–6–5–5–5–4–4–4–3–3–3–2–2–2–1–1–1111222333444555666777888–3–3–3–2–2–2–1–1–1111222333444555666000

Video Solution

Solution Steps

00:00 Find the appropriate equation for the function in the table
00:03 We want to find the slope of the graph
00:07 Let's take 2 points on the graph
00:10 We'll use the formula to find the function's graph slope
00:14 We'll substitute appropriate values according to the given data and solve to find the slope
00:24 This is the slope of the graph
00:29 We'll use the linear equation
00:32 We'll substitute appropriate values and solve to find B
00:44 This is the value of B (Y-axis intercept)
00:50 We'll construct the linear equation using the values we found
00:54 And this is the solution to the question

Step-by-Step Solution

To match the graph to the correct equation, we will analyze the slope and y-intercept:

  • Step 1: Identify y-intercept.
    From the graph, observe that the line crosses the y-axis at y=4 y = 4 . Therefore, the y-intercept b=4 b = 4 .

  • Step 2: Calculate slope.
    Identify two points on the graph line, such as (0,4) (0, 4) and (5,0) (5, 0) . Calculate slope using m=ΔyΔx m = \frac{\Delta y}{\Delta x} :
    m=0450=45 m = \frac{0 - 4}{5 - 0} = \frac{-4}{5} .

  • **Step 3: Match to equations**.
    Now we have m=45 m = -\frac{4}{5} and b=4 b = 4 , so the equation should be y=45x+4 y = -\frac{4}{5}x + 4 .

After comparing with the choices, we see that choice (2)(2) y=45x+4 y = -\frac{4}{5}x + 4 correctly matches the information derived from the graph.

Therefore, the equation that corresponds to the graph is y=45x+4 y = -\frac{4}{5}x + 4 .

Answer

y=45x+4 y=-\frac{4}{5}x+4