If x4 + x2y2 + y4 = 156,
x2 + xy + y2 = 13, then
find x2 - xy + y2 .
Answer & explanation
Correct answer: option 2
Formula → x4 + y4 + x2y2 = (x2 + y2 + xy) × (x2 + y2 - xy)
⇒ 156 = 13 × (x2 + y2 - xy)
⇒ x2 + y2 - xy = \(\frac{156}{21}\) = 12
If x4 + x2y2 + y4 = 156,
x2 + xy + y2 = 13, then
find x2 - xy + y2 .
Correct answer: option 2
Formula → x4 + y4 + x2y2 = (x2 + y2 + xy) × (x2 + y2 - xy)
⇒ 156 = 13 × (x2 + y2 - xy)
⇒ x2 + y2 - xy = \(\frac{156}{21}\) = 12