(a-b)2+—=a2-b2
Explanation:
We have to find the value of the blank . Let —=x
It means we find the value of x.
We know that
(a-b)2=(a-b)(a-b)=a2-ab-ba+b2(aftermultiplyingthebrackets)=a2-ab-ab+b2(ab=ba)=a2-2ab+b2
So (a-b)2+x=a2-b2x=a2-b2-(a-b)2x=a2-b2-(a2-2ab+b2)x=a2-b2-a2+2ab-b2(duetominussignthesignofthetermswithinthebracketchanges)x=2ab-2b2(herea2iscancelledby)
Hence, 2ab-b2 is the required answer.
Which of the following is correct? a) (a−b)2=a2+2ab−b2 b) (a−b)2=a2−2ab+b2 c) (a−b)2=a2−b2 d) (a+b)2=a2+2ab−b2