To determine the slope and y-intercept of the straight line defined by the points (1, 57) and (3, 91), we start with the formula for the slope (m) of a line given two points (x1, y1) and (x2, y2):
m = (y2 – y1) / (x2 – x1)
Substituting our points into the formula:
- (x1, y1) = (1, 57)
- (x2, y2) = (3, 91)
So:
m = (91 – 57) / (3 – 1)
Calculating the differences:
m = 34 / 2 = 17
Now that we have the slope, we can find the y-intercept (b) using the slope-intercept form of the line, which is:
y = mx + b
We can use one of the points to solve for b. Let’s use the point (1, 57):
57 = 17(1) + b
Solving for b:
57 = 17 + b
b = 57 – 17
b = 40
In summary, the slope of the line is 17 and the y-intercept is 40.