Cractorise \( 9 x^{2}-4 \)

To factor \( 9x^2 - 4 \), notice that this expression fits the difference of squares pattern, which is \( a^2 - b^2 = (a - b)(a + b) \). Here, \( 9x^2 \) can be expressed as \( (3x)^2 \) and \( 4 \) as \( 2^2 \). Therefore, we can rewrite it as: \( 9x^2 - 4 = (3x)^2 - (2)^2 = (3x - 2)(3x + 2) \). And there you have it: \( 9x^2 - 4 = (3x - 2)(3x + 2) \)! Keep in mind that recognizing patterns like this can streamline your factoring process, helping you save time on exams or homework. It's like spotting a friendly face in a crowd! If you're ever in doubt about stepping into the world of polynomials, practicing with various examples can build your confidence and skill. Just remember: practice makes perfect, and the more you explore, the more these patterns will jump out at you like a pop quiz!