Mathematics for IGCSE & O level - Algebraic Manipulation (Section 3 - No. 3)
Which expressions can be factored using the difference of squares?
9x² - 4
x² + 4
16x² - 25
x² + 6x + 9
解释
The difference of squares is a² - b²; so 9x² - 4 and 16x² - 25 can be factored.