If p + q = 12 and pq = 14, then find the value of p2 - pq + q2.
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Correct answer: C
Explanation
The correct answer is option 3 i.e. 102.
p + q = 12
⇒ (p + q)2 = 122
⇒ p2 + 2pq + q2 = 144
⇒ p2 + (2 × 14) + q2 = 144
⇒ p2 + q2 = 144 - 28 = 116
⇒ p2 - pq + q2 = 116 - 14 = 102