The images show graphs of functions of the form y = kx + b. Match the signs of the coefficients k and b with the function graphs. Drag the function graphs to the corresponding coefficients.

INSIGHT

Solution

The equation of a line is given by $$y = kx + b$$. Here, $$k$$ is the slope and $$b$$ is the y-intercept.

• Case 1: $$k < 0, b < 0$$
  If $$k < 0$$, the line slopes downwards from left to right. If $$b < 0$$, the line intersects the y-axis below the origin. The graph that fits this description is the first graph.
• Case 2: $$k < 0, b > 0$$
  If $$k < 0$$, the line slopes downwards from left to right. If $$b > 0$$, the line intersects the y-axis above the origin. The graph that fits this description is the second graph.
• Case 3: $$k > 0, b < 0$$
  If $$k > 0$$, the line slopes upwards from left to right. If $$b < 0$$, the line intersects the y-axis below the origin. The graph that fits this description is the third graph.