2 (a2 + b2) = কত?
A
a+b2-a-b2
B
a-b2-a+b2
C
a+b2+a-b2
D
a+b2-4ab
Correct Answer: a+b2+a-b2
(a+b)2=a2+2ab+b2(a-b)2=a2-2ab+b2----------------(a+b)2+(a-b)2= 2(a2+b2)