100000=1500000*(1-c)^8
Divide both sides by 1500000
(1-c)^8 = 1/15
Take the eighth root
1-c = sqrt(1/15, 8)
Subtract 1
-c = sqrt(1/15, 8) - 1
Multiply by -1
c = 1 - sqrt(1/15, 8)
+44 
