When deriving the Adams-Bashforth 2 step predictor, one must calculate the integral of:

t-tj-1/tj-tj-1 f(tj,y(tj)) + t-tj/tj-1-tj f(tj-1,y(tj-1))

between the limits tj and tj+1, where f(t,y) is dy/dt...

How does one go about doing this integral, is there a clever substitution that must be made.. can any1 help???