Mathematics for IGCSE & O level - Equations (Section 6 - No. 2)
Which of the following is equivalent to completing the square for the expression x² + 6x + 5?
(x+3)² - 4
(x+3)² + 14
(x-3)² - 4
(x+3)² + 4
คำอธิบาย
Completing the square: (x + b/2)² - (b/2)² + c. Here, (x+3)² - 9 + 5 = (x+3)² - 4.