b) 12 - [ 5^2 - (1/2 - 1/3)^ 2] . ( 1/ 3 - 2/5)^4 : ( 1 + 3/ 5)^ 3

b)  12−52−12−132.13−254:1+353 = 12−25−36−262.515−6154:55+353

 =12−25−162.−1154:853=12−25−136.1154:8533=12−89936.1154:8353 

=12−89936.1154.5383=12−899.5336.3.54.83=12−899.5336.34.54.83=12−89936.34.5.83

= 12 – 8997464960  = 895786217464960 .