Question

if (a-5) 2 +(b-c) 2 +(c-d) 2 +(b+c+d-9) 2 =0, then the value of (a+b+c)(b+c+d) is

Answer 1

or,a=5,b=c=d,b+c+d=9
b=c=d=3
(a+b+c)(b+c+d)
=(5+3+3)×9
=99