যদি x-y2 = 12 এবং xy = 1 হয়, তবে x2+y2 = কত?
A
14
B
11
C
12
D
13
Correct Answer: 14
(x - y)2 = x2 - 2 . x . y + y212 + 2 = x2 + y2So, x2 + y2 = 14