Question

Enter the system represented on the graph below. Find and explain the meaning of the point of intersection of the lines.

Answer 1

y = -2x+4

y = (3/2)x -3

The point of intersection is (2, 0), or x=2 and y=0.

Explanation:

The downward-sloping line drops 2 grid squares for each 1 it goes to the right, so its slope is -2. It intersects the y-axis at +4. In slope-intercept form, its equation is ...

y = slope · x + (y-intercept)

y = -2x + 4

Similarly, the upward-sloping line rises 3 grid squares for each 2 it goes to the right, so its slope is 3/2. It intersects the y-axis at -3. Its equation is ...

y = (3/2)x -3

The two lines intersect at the point where x=2 and y=0, so the coordinates are (2, 0). These are the values of x and y that satisfy both equations, so are the solution to the system.