Question

Sa se descompună in factori : 9x la a patra - 1

Answer 1

$9 {x}^{4} - 1= (3 {x}^{2} - 1)(3 {x}^{2} + 1) = {(3 {x}^{2} )}^{2} - {1}^{2}$

${a}^{2} - {b}^{2} = (a - b)(a + b)$