if a(a,b,c,d) means you take the square root of the sum of the terms and a(8,10,13,d)=6,then d= a:5 b:6 ...

if a(a,b,c,d) means you take the square root of the sum of the terms and a(8,10,13,d)=6,then d= a:5 b:6 c:12 d:18 e:36