Special Products 4

= \({\left(A+B\right)}^3\) , where \(A=9x\) and \(B=4{y}^{3}\)

= \(A^3+3A^2B+3AB^2+B^3\)

= \({\left(9x\right)}^{3}+3{\left(9x\right)}^{2}\left(4{y}^{3}\right)+3\left(9x\right){\left(4{y}^{3}\right)}^{2}+{\left(4{y}^{3}\right)}^{3}\)

= \(729{x}^{3}+3\left(81{x}^{2}\right)\left(4{y}^{3}\right)+3\left(9x\right)\left(16{y}^{6}\right)+64{y}^{9}\)

= \(729{x}^{3}+972{x}^{2}{y}^{3}+432x{y}^{6}+64{y}^{9}\)