Respuesta :
(7x - 2)(7x + 7)
= 7x * 7x + 7x * 7 - 2 * 7x - 2 * 7
= 49x² + 49x - 14x - 14
= 49x² + 35x - 14
= 7x * 7x + 7x * 7 - 2 * 7x - 2 * 7
= 49x² + 49x - 14x - 14
= 49x² + 35x - 14