Question

quanto e (x²+2).(x²+6)

Answer 1

$x^{4}$+6x²+2x²+12
$x^{4}$+8x²+12

Answer 2

= (x² + 2).(x² + 6) 
= x².x² + 6.x² + 2.x² + 2.6
= x⁴ + 6x² + 2x² + 12
= x⁴ + 8x² + 12