To write the equation of the line that passes through (10,80) (5,65)
we will use the formula;
x₁ = 10 y₁ = 80 x₂ = 5 y₂ = 65
substituting the above into the formula;
we will go ahead and simplify
y- 80 = 3(x - 10)
y- 80 = 3x - 30
y -3x -80 + 30 = 0
y - 3x - 50 = 0
The above is the equation of the line.
To write in a slope-intercept form simply means to write it in the form;
y = mx + b
where m is the slope and b is the intercept
Hence;
y = 3x + 50
The above is the equation of the line in a slope-intercept form