Math
posted by Christopher .
The first three terms of an arithmetic progression are t, 2t1, 2t+4. Calculate the value of t.

To be an arithmetic progression,
(2t1)  t = (2t+4)  (2t1)
solve for t 
2.5

(2t1)t=(2t+4) (2t1) 2t1t=2t+42t+1 collect like terms 2t2t+2t=4+1+1 2t=6 divide 2 both side 2t/2=6/2 t=3