SOLUTION: X+y=a and x2+y2=b then value of x3+y3 will be

You are given

x + y = a,           (1)
 = b           (2)

You are asked to find the value of .

Square the equality (1) (both sides). You will get

 = .     (3)

Subtract (2) from (3) (both sides). You will get

2xy = .         (4)

Now we are ready to evaluate .


   =        (I suppose you know this classic/basic factoring)

=                  (I just replaced the factor x+y by its value a, according to (1))

=                 (I just replaced  by 'b' and replaced  xy  by  , due to (4) )

=  = .