a + b = √7, a - b = √5 হলে, 8ab(a2 + b2) = ?

প্রশ্ন: a + b = √7, a - b = √5 হলে, 8ab(a2 + b2) = ?সমাধান:দেওয়া আছে,a + b = √7a - b = √5এখন,8ab(a2 + b2)= 4ab × 2(a2 + b2)= {(a + b)2 - (a - b)2} × {(a + b)2 + (a - b)2}= {(√7)2 - (√5)2} × {(√7)2 + (√5)2}= (7 - 5) × (7 + 5)= 2 × 12= 24