Question

x+x-1+x-2+x-3+x-4+...+x-50 = 255

Answer 1

51x - ( 1+2+3+4+....+50) = 255

51x - 1275 = 255

51x = 255 + 1275

51x = 1530

x= 1530 : 51 

x =30

Answer 2

x+x-1+x-2+x-3+x-4+...+x-50 = 255

 51x - (50 + 49 + 48 + ....+ 1) = 25551x - 1275 = 25551x 255 + 127551x = 1530x = 1530 : 51x = 30