Answer:
Explanation:
Given a straight line defined by the points (1,51) and (3,91),
x1 = 1, y1 = 51, x2 = 3 and y2 = 91
Slope of the line m = ∆y/∆x
m = y2-y1/x2-x1
m = 91-51/3-1
m = 40/2
m = 20
Hence the slope of the line is 20.
Given the equation of a line y = mx+c
To get the y intercept of the line c, we will substitute one of the give points and the slope into the equation as shown;
Using the point (1,51) and m = 20,
Substitute into the equation y = mx+c
51 = 20(1)+c
51 = 20+c
c = 51-20
c = 31
Hence the slope is 20 and the y intercept of the line is 31