JAMB - Mathematics (2001 - No. 13)
Factorize 4x2 - 9y2 + 20x + 25
(2x -3y + 5)(2x - 3y - 5)
(2x - 3y)(2x + 3y)
(2x - 3y +5)(2x + 3y + 5)
(2x + 5)(2x - 9y +5)
คำอธิบาย
Given: 4x2 - 9y2 + 20x + 25
Collect like terms: 4x2 + 20x + 25 - 9y2
(2x + 5)(2x + 5) - 9y2
(2x + 5)2 - (3y)2
(2x - 3y +5)(2x + 3y + 5)
Collect like terms: 4x2 + 20x + 25 - 9y2
(2x + 5)(2x + 5) - 9y2
(2x + 5)2 - (3y)2
(2x - 3y +5)(2x + 3y + 5)