a + b = √7 এবং a - b = √5 হলে, 8ab(a2 + b2) = কত?
সমাধান
সঠিক উত্তর: Option C
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
=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
