The answer to this problem is 5/24. First you find the LCM that is 48. Then you multiply 1 by 8 and get 8 so that fraction is 8/48. Then you multiply 5 by 4 and get 20 put that into a fraction and subtract then you reduce the fraction.
Finding an equation of a tangent line to that function requires that we find the derivative of the function at that point. Since this is an absolute value function with its cusp at (2, 5), the function is not differentiable here.