Special Products 4

= \({\left(A+B\right)}^3\) , where \(A=2x\) and \(B=7y\)

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

= \({\left(2x\right)}^{3}+3{\left(2x\right)}^{2}\left(7y\right)+3\left(2x\right){\left(7y\right)}^{2}+{\left(7y\right)}^{3}\)

= \(8{x}^{3}+3\left(4{x}^{2}\right)\left(7y\right)+3\left(2x\right)\left(49{y}^{2}\right)+343{y}^{3}\)

= \(8{x}^{3}+84{x}^{2}y+294x{y}^{2}+343{y}^{3}\)