Given two points (x₁,y₁) and (x₂,y₂), the slope of the line passes throught of these points will be:
m=(y₂-y₁)/(x₂-x₁)
If we want to find the equation of a line, we only need a point (x₀,y₀) and the slope: Point-slope form: y-y₀=m(x-x₀)
a) (6,1) (5,4) 1)we find the slope of the line passes through these points. m=(4-1)/5-6)=3/-1=-3
2)We find the equation of the line: We can choose either points of two points if we chose the point (5,4) y-y₀=m(x-x₀) y-4=-3(x-5) (point-slope form) y-4=-3x+15 y=-3x+19 (slope intercept form)