If a2+b2 = 5ab, then value of a2b2+ b2a2 is
A
16
B
23
C
-16
D
-23
Correct Answer: 23
দেওয়া আছে, a2 + b2 = 5ab >a2ab + b2ab = 5 > ab + ba = 5 এখন, ab2 + b2a2 = (ab)2 + (ba)2 = (ab + ba)2 - 2×ab×ba = 52 - 2 = 25 - 2 = 23