I need a detailed version on how to find the scant lineequation for this specific problem. Let \( h(x)=x^{2}-4 x \) (a) Find the average rate of change from 8 to \( 9 . \) (b) Find an equation of the secant line containing \( (8, h(8)) \) and \( (9, h(9)) \). (a) The average rate of change 1 answer