Problem: a+b = $\sqrt{7}$ এবং a-b = $\sqrt{5}$ হলে, $8ab(a^{2}+b^{2})$ = ?
View all: BANGLADESH HOUSE BUILDING FINANCE CORPORATION | DATA OPERATOR-2023 । WRITTEN MATH SOLVE
Correct Answer: 24
Explanation:
Here, $8ab(a^{2}+b^{2})$=$ 4ab x 2(a^{2}+b^{2})$
= $[(a+b)^{2}-(a-b)^{2}] [(a+b)^{2}+(a-b)^{2}]$
=$[ (\sqrt{7})^{2}- (\sqrt{5})^{2} ][(\sqrt{7})^{2}+ (\sqrt{5})^{2}]$=24
