Szkoła podstawowa
Wzór na różnicę kwadratów dwóch liczb jest następujący: \[a^2-b^2=(a-b)(a+b)\]
- \(x^2 - 4 = x^2 - 2^2 = (x - 2)(x + 2)\)
- \(x^2 - 9 = x^2 - 3^2 = (x - 3)(x + 3)\)
- \(x^2 - 25 = x^2 - 5^2 = (x - 5)(x + 5)\)
- \(x^2 - 36 = x^2 - 6^2 = (x - 6)(x + 6)\)
- \(x^2 - 49 = x^2 - 7^2 = (x - 7)(x + 7)\)
- \(x^2 - 144 = x^2 - 12^2 = (x - 12)(x + 12)\)
- \(81 - x^2 = 9^2 - x^2 = (9 - x)(9 + x)\)
- \(x^2 - 2 = x^2 - (\sqrt{2})^2 = (x - \sqrt{2})(x + \sqrt{2})\)
- \(x^2 - 5 = x^2 - (\sqrt{5})^2 = (x - \sqrt{5})(x + \sqrt{5})\)
- \(x^2 - 0{,}25 = x^2 - 0{,}5^2 = (x - 0{,}5)(x + 0{,}5)\)