Evaluate :

`( a + b )( a - b ) + ( b + c ) ( b - c ) + ( c + a ) ( c - a )`

Find the value of ( a - b ) times ( a + b ) + ( b -c ) times ( b + c ) + ( c + a ) times ( c - a ) = A) -1 B) 0 C) 1

If a + b + c = 0 , then find the value of ( ( a + b ) / c + ( b + c )/a + ( c + a ) / b ) times ( a /( b + c ) + b /( c + a ) + c /( a + b ) ) is :

If a ,\ b ,\ c are in proportion, then (a) a : b :: b : c (b) a : b :: c : a c) a : b :: c : b (d) a : c :: b : c

Find x in terms of a , b and c : (a)/(x - a) + (b)/(x - b) = (2 c)/(x - c) , x - a , b , c