Au trimis soluţii complete: Ady Nicolae, Aurel Ionescu, Zoltan Szabo, Camelia Muşetescu.

Parţial: Monica Asănăchescu, Ştefan Gaţachiu

Am selectat cele mai bune variante:

0= 2x0x1x5 = 2x0x15

1 = 2+0-15 = 2+0+1-[sqrt(5)]

2 = -2-0-1+5 = 2+0x1x5 =  20 +15

3 = -2 -0+1x5 = 2+0+15     

4 = (20x1)/5 =20/(1*5) = 2x0-1+5 = -(20)+1x5

5 = 20-15 = 2x0x1+5

6 = 2x0+1+5= 20+1x5

7 = 2+0x1+5= 2+0+1x5

8 = 2+0+1+5

9=2+0!+1+5 = [sqrt(20)]+1x5

10 = (2+0x1)x5 =  ( 2+0)x1x5 =2x(0x1+5) = 2x(0+1x5)

11 = (2+0+1)!+5  = (2+0!)! x 1 + 5 = (2+0!)!+1x5=[sqrt(sqrt(20))*1*5]= [sqrt(201)-sqrt(5)] =2x0+1+[sqrt(5!)] =[ln(201)xsqrt(5)] =[20ln(sqrt(5))]

12 = (2+0)x(1+5) = 2x(0+1+5) = (2+0!)!+1+5 =[sqrt(201)-ln(5)] =[sqrt(sqrt(20))*(1+5)]

13 = -2+0+15 = 2+0+1+[ sqrt(5!)] =[(20+1)/ln(5)]

14 = 20-1-5 = [sqrt(sqrt((2-0+1+5)!)] = 2+0!+1+[(sqrt(5!)]

15 = 20x1-5=20-1*5=(2+0+1)x5

16=20+1-5 = 20-(-1+5) = 20-1+5 = (2+0)-(1-5)  = [sqrt(201)+sqrt(5)]

17 = 2+0+15 = 20-[sqrt(15)]=[ln((2+0+1)!+5)!] = (2+0!)!+1+[sqrt(5!)]

18 = 2+0!+15 =(2+0!)x(1+5)=20 - [ln(15)] = 20-[sqrt(1+5)]

19 = 20-15 = (2+0!+1)! - 5=[sqrt(201)+5] =[sqrt(20)+15]=20+1-[sqrt(5)]

20 = 20x15 = (2+ 0!+1)x5 =[20+lg(1+5)]

21 = 20+15 = -2-0!+(-1+5)! =20-1+[sqrt(5)] =[20+ln(1)+ln(5)]

22 = -2+0+(-1+5)! = 20x1+[sqrt5] =20+1x[sqrt(5)]=20+1+[ln5] =20+ln1+[sqrt(5)] =[ln(2+0+1+[sqrt(5!)])!]

23 = 20+1+[sqrt(5)] = -2+0!+(-1+5)!=20+[sqrt(15)]

24 = 20-1+5 = 2x0+(-(1-5))! = [sqrt(20)]x(1+5)

25 = 20x1+5 20+1x5= 201+5 =2-0!+(-1+5)!=20+ln(1)+5 = 2+ (-1+5)!  

26 = 20+1+5 = 2x(0!)+(-1+5)! = 2x0+[sqrt((1+5)!)]                

27 = [sqrt(20)]! + [sqrt(15)] =[sqrt(20)]!+1+[sqrt(5)]= 2+0!+(-1+5))! =[sqrt(sqrt(sqrt(201)5))]

28 = [sqrt(20)]! -1+5=[sqrt(5)]!-1+5 = 2+0+[sqrt((1+5)!)] =[sqrt(201)x[sqrt(5)]]

29 = [sqrt(20)]! + 1x5 = 20-1+[sqrt(5!)]= (2+0!+1)!+5 = 2+0!+[(sqrt((1+5)!)) =[20/lg(ln(1)+5)] =[2+0+ln(15!)]

30=(2+0)x15 = (2+0+1)!x5 = 2 x (0!) x15=[(20+1)/lg(5)]

31=20+sqrt(1+5!) = -[sqrt(2)]+(0!+1)5 =[sqrt(201x 5)]= [sqrt(((2+0!)!)!)]x1 + 5

32 = (2+0x1)5 =(2+0)1*5  = 20x1+5

33=[sqrt(2)] + (0!+1)5 =  [20lg(15)] = [ln([ln(2+0+1)!+5)!]!)]  

34=2+(0!+1)5=[sqrt(sqrt(20)sqrt(-1+5)!)] = [sqrt((((2+0!)!)!) x 1 x ln5)]

35 = 20+15= ((2+0!)!+1)x5

36 = (2+0!)! x(1+5) = [sqrt(sqrt(20!/15!))]

37=[ln(20!)-ln(1)-5]= -(2+0+1)!+[sqrt(sqrt(([sqrt(5!)])!))] =[[sqrt(sqrt(sqrt(sqrt20!)))] x ln15]

38=(20-1)*[sqrt(5)]=[ln(20!)+1-5] = [sqrt(sqrt(sqrt(20!))) x ln15] =

39=[sqrt(20)]!+15 = [ln(20!) – ln(15)]=[sqrt(20sqrt(1+5))] = [ln([ln(2x(0+1+5))!]!)]

40 = [201/5] =20*1*[sqrt(5)]= arctg(2+0-1)-5      

41 = [sqrt(((2+0!)!)!)] + 15=[ln(201)sqrt(5)]

42=(20+1)*[sqrt(5)] = ((2+0!)! + 1)! / 5!= (2+0!)!+1)x([sqrt(sqrt(5!))]! =[sqrt(sqrt(20)ln(1)+5)]

43=[ln((2+0!)!)(-1+5)!] = [sqrt(sqrt((2+0)x1x5)!))]= [sqrt([log201)]! x 5)] =2x0x1+[sqrt(sqrt([sqrt(5!)]! ))]

44=20+(-1+5)! = [sqrt(2015)] = 2x0+1+[sqrt(sqrt([sqrt(5!)]!))]

45 = (2+0!)! x 15= 2+0x1+[sqrt(sqrt([sqrt(5!)]!))]

46= [ln(20!)]-1+5=([sqrt(20)]!-1)*[sqrt(5)] = 2+0+1+[sqrt(sqrt([sqrt(5!)]!))]

47=20+[ln(15!)] = [sqrt((((2+0!)!)!) log15)] = arctg(2+0-1) + [sqrt(5)]= 2+0!+1+[sqrt(sqrt([sqrt(5!)]!))]

48 = (2+0)x((-1+5)!) = ((2+0!)!)!/15=[20x sqrt(1+5)] =(2+0!+1)! x[sqrt(5)]

49 = [sqrt(sqrt(sqrt(sqrt(20!))))x1+sqrt(sqrt(sqrt(sqrt(sqrt(sqrt(sqrt(5!)!))))))]=  

50=[ln((20+1)!)+5] = ([sqrt(20)]!+1)*[sqrt(5)]= [sqrt(((2+0!)!+1)!) / [sqrt(5)])] =arctg(2+0-1) +5

51 = [log(20!) + sqrt(sqrt(sqrt(15!)))] = [lg(([sqrt(sqrt(20)ln(1)+5)])!)]

52 = 20 + [sqrt(sqrt(sqrt(15!)))]=[lg(([ln(((2+0!)!)(-1+5)!])!)]

53 = [((2+0!)!-1)! / sqrt(5)]=[sqrt(sqrt((2+0!+1)!)5)]

54 = [20 x ln15]

55=[sqrt([ln(201)]5)] = [sqrt(((2+0!)!+1)!