A straight line runs through these two coordinates (1,5) and (4,7), find the equation of the line.

Given that the equation is a straight line we know that it will take the form of y = mx + c with m as the gradient and c as the y-intercept. We can find the slope by doing (y₁- y₂)/(x₁-x₂) = m , if we sub in we get (5-7)/(1-4) = 2/3 we then have this eqn: y = 2/3x +c , we can then find c by subbing in either one of our coordinates: 5 = 2/3(1) + c = 13/3. The eqn of the line is: y = 2/3x + 13/3