What does this mean.

I need some help please in understanding move analysis? Below is an analysis that was given me in "tactics" Example from below (12:2.78 39...Rxa440) - what does this mean? And there are also multiple #12 equations?

Any help would be appreciated. Thank you

39... Rxa4

(12:+2.78 39... Rxa440. Rxc5+Kxc541. Rxa4h542. Kd3hxg443. hxg4f544. gxf5gxf545. Nxf5Ra8)

(12:-2.71 39... Nxa440. Rd2Nb641. Kd3Kc542. Rc1a443. Kc3Rd744. Kd3Rc745. h4)

(12:-2.32 39... h640. Rad1Rd741. Ra1f542. gxf5gxf543. Nxf5Rxc444. Rd2d545. Nxh6Nxa4)

(12:-2.40 39... Rd740. Rd2Nxa441. Kd3Kc542. Ke2f543. gxf5gxf544. Rc1Nb645. Kd3)

There are spaces missing which is not helping.

So 

(12:+2.78 39... Rxa440. Rxc5+Kxc541. Rxa4h542. Kd3hxg443. hxg4f544. gxf5gxf545. Nxf5Ra8)

should be

(12: +2.78 39… Rxa4 40. Rxc5+ Kxc5 41. Rxa4 h5 42. Kd3 hxg4 43. hxg4 f5 44. gxf5 gxf5 45. Nxf5 Ra8)

So it should be clear that if black plays 39. … Rxa4 there will be an advantage to white of +2.78 units. 

It is suggested that white will play Rxc5 and then black will play Kxc5 and then black will play Rxa4. 

Thank you for explaining this to me.

If 39 the move number? If so, then what is 12 for?

I don't know what the 12 is for. 

Thanks for reply

I am assuming you are familiar with chess notation

https://en.wikipedia.org/wiki/Algebraic_notation_(chess)

Thank you for helping me corum, I appreciate the effort