Expression 30: "t" Subscript, 1 , Baseline equals StartFraction, "b" Subscript, 2 , Baseline "B" Subscript, 1 , Baseline minus "b" Subscript, 1 , Baseline "B" Subscript, 2 , Baseline plus "b" Subscript, 1 , Baseline "O" Subscript, 2 , Baseline minus "b" Subscript, 2 , Baseline "O" Subscript, 1 , Baseline Over "a" Subscript, 2 , Baseline "b" Subscript, 1 , Baseline minus "a" Subscript, 1 , Baseline "b" Subscript, 2 , Baseline , EndFractiont1=b2B1−b1B2+b1O2−b2O1a2b1−a1b2