1.7 x 10^-3 = (0.0015 - x)^2 / (0.025 +1/2x) (0.025 + 1/2x)
solve for x
Does (0.025 + 1/2x) occur twice? It's hard to tell. If it does, and multiplies as written, then you just have
1.7 x 10^-3 = (0.0015 - x)^2
0.0015 - x = ±0.041
and that you can handle.