To write an equation in slope-intercept form, which is expressed as y = mx + b, we first need to determine the slope (m) of the line that passes through the two given points: (3, 1) and (2, 5).
The formula for the slope (m) between two points (x1, y1) and (x2, y2) is:
m = (y2 – y1) / (x2 – x1)
Using our points, (x1, y1) = (3, 1) and (x2, y2) = (2, 5), we can substitute these values into the slope formula:
m = (5 – 1) / (2 – 3) = 4 / -1 = -4
Now that we have the slope, m = -4, we can use one of the points to find the y-intercept (b). We can use the point (3, 1) for this example.
We substitute the x and y values into the slope-intercept equation:
1 = -4(3) + b
This simplifies to:
1 = -12 + b
Now, add 12 to both sides to solve for b:
b = 1 + 12 = 13
Now we have the slope and the y-intercept. We can write the final equation in slope-intercept form:
y = -4x + 13