So the investment in 20 14 years is 25 million yuan (1+x), and the investment in 20 15 years is 2500 yuan (1+x)?

Column equation

2500( 1+x)？ = 3600

2500( 1+2x+x？ )=3600

25+50x+25x？ =36

25x？ +50x- 1 1=0

Solve by formula method

X=0.2=20% or x=- 1 1/5 (s).

Answer,