Question

calcule (1-9z)ao quadrado=

Answer 1

 (1-9z)ao quadrado=

 (1-9z)^2 =  1^2 + 2.1(-9z) +(9z)^2

   1 - 18z + 81z^2

Answer 2

$(1-9z)^2=1^2-2.1.9z+9z^2=\boxed{1-18z+81z^2}$