Question

Expand 9x -y square +z upon 3 whole square​

Answer 1

Answer:

$(9x - 3 {)}^{2} + {(z \div 3)}^{2} \\ (a - b {)}^{2} = {a}^{2} - 2ab + {b}^{2} \\ applying \: above fomula \: we \: get \: \\ 81 {x}^{2} -2xy + {y}^{2}$

and (z/3)^2 = Z square /9

now add these two terms yourself