` 1B `
` a) ` ` (x + 3)^{3} = x^{3} + 3(3x^{2}.3) + 3(3x.3^{2}) + 3^{3} = x^{3} + 27x^{2} + 81x + 27 `
` b) ` ` (1/2 - x)^{3} = (1/2)^{3} - 3.(1/2)^{2}x + 3.1/2 x^{2} - x^{3} = 1/8 - 3/4 x + 3/2 x^{2} - x^{3} `
` c) ` ` (2x - y^{2})^{3} = 2x^{3} - 3.2x^{2}y^{2} + 3.2xy^{4} - y^{6} = 2x^{3} - 6x^{2}y^{2} + 6xy^{4} - y^{6} `
` d) ` ` (2x - \frac{y^2}{x})^{3} = 2x^{3} - 3.2x^{2}.\frac{y^{2}}{x} + 3.2x.(\frac{y^{2}}{x})^{2} - (\frac{y^{2}}{x})^{3} = 2x^{3} - 6xy^{2} + \frac{6y^{4}}{x} - \frac{y^{6}}{x^{3}} `
