JAMB - Mathematics (1984 - No. 23)
Find a factor which is common to all three binomial expressions 4a2 - 9b2, 8a3 + 27b3, (4a + 6b)2
4a + 6b
4a - 6b
2a + 3b
2a - 3b
none
Vysvětlení
4a2 - 9b2, 8a3 + 27b3, (4a + 6b)2 = (2a + 3b)(2a - 3b)
8a3 + 27b3 = (2a)3 + (3b)3
= (2a + 3b)(4a - 6ab = 9a2)
(4a + 6b)2 = 2(2a + 3b)2
8a3 + 27b3 = (2a)3 + (3b)3
= (2a + 3b)(4a - 6ab = 9a2)
(4a + 6b)2 = 2(2a + 3b)2