4x2+4bx−(a2−b2)=0
4x2+4bx−a2+b2=0 [ 1 mark]
(2x)2+2.(2x).b+b2−a2=0 [1 mark]
(2x+b)2−a2=0 (2x+b+a)(2x+b−a)=0 x=−(b+a)2 or x=a−b2 [ 1 mark]
Solve each of the following equations by using the method of completing the square: 4x2+4bx−(a2−b2)=0