25,-10,4 evaluate converges
ended up with 10/7, is that right?
assuming the obvious,
a GS with a = 25 and r = -.4 or -4/10 , and you are adding them.
sum of infinite number of terms = a/(1-r)
= 25/(1+4/10)
= 25 /(14/10)
= 25(10/14)
= 250/14 = 125/7