Mathematics for IGCSE & O level - Algebraic Manipulation (Section 1 - No. 37)
What is the factored form of the expression x² - 49?
(x - 7)(x - 7)
(x + 7)(x + 7)
(x - 7)(x + 7)
(x - 14)(x + 3)
解释
The difference of squares, a² - b², factors into (a - b)(a + b).