Question

Resolva a multiplicação: (3x − y).(3x + y).(2x − y)

Answer 1

(9x - y(ao quadrado) . (2x - y)
(18x - y)

Answer 2

= (3x − y).(3x + y).(2x − y)

= (3x.3x + 3x.y - 3x.y - y.y) . (2x - y)

= (9x² + 3xy - 3xy - y²).(2x - y)

= (9x² - y²).(2x - y)

= 9x².2x + 9x².(-y) - y².2x - y².(- y) 

= 18x³ - 9x²y - 2xy² + y³