JAMB - Mathematics (2021 - No. 35)
Factorize completely 81a\(^4\) - 16b\(^4\)
(3a + 2b)(2a - 3b)(9a2 + 4b2)
(3a - 2b)(2a - 3b)(4a2 - 9b2)
(3a - 2b)(3a + 2b)(9a2 + 4b2)
(6a - 2b)(8a - 3b)(4a3 - 9b2)
توضيح
81a\(^4\) - 16b\(^4\) = (9a\(^2\))\(^2\) - (4b\(^2\))\(^2\)
= (9a\(^2\) + 4b\(^2\))(9a\(^2\) - 4b\(^2\))
N:B 9a\(^2\) - 4b\(^2\) = (3a - 2b)(3a + 2b)
= (9a\(^2\) + 4b\(^2\))(9a\(^2\) - 4b\(^2\))
N:B 9a\(^2\) - 4b\(^2\) = (3a - 2b)(3a + 2b)