Respuesta :

(9t-4)(-9t-4)

using the FOIL :

9t * -9t = -81 t^2
9t * -4 = -36 t
-4 * -9t = 36 t
-4 * -4 = 16
-----------------------add up and simplify

[tex]-81 t^2 -36 t + 36 t +16 = -81 t^2 +16[/tex]

Ver imagen 3mar