Question

(14+х)(14-х);(5a+3b)(3b-5a);(2n²+n)(n-2n²)

Answer 1

а) (14 + x)(14 - x) = 196 - x²
б) (5a + 3b)(3b - 5a) = 9b² - 25a²
в) (2n² + n)(n - 2n²) = 4n⁴ - n²

а) x² - 121 = (x - 11)(x + 11)
б) -0,04a² + b²c² = (bc - 0,2a)(bc + 0,2a)
в) (x - 1)² - 9 = (x - 1)² - 3² = (x - 1 - 3)(x - 1 + 3) = (x - 4)(x + 2)

x² - (x - 4)(x + 4) = 2x
x² - x² + 16 = 2x
16 = 2x
x = 8

25x² - 16 = 0
(5x - 4)(5x + 4) = 0
5x - 4 = 0 и 5x + 4 = 0
x = 0,8 и x = -0,8