a) [tex]\frac{1}{3} x^{3}y = \frac{1}{3} * (-2)^{3} * (-1) = \frac{1}{3} * (-8) * (-1) = \frac{9}{3} = 3[/tex]
b) [tex]-\frac{1}{2} xy^{2} = -\frac{1}{2} * (-2) * (-1)^{2} = -\frac{1}{2} * (-2) * (-1) = -1[/tex]
c) [tex]2\frac{3}{4}(x^{2} - y^{2} ) * x^{2} y = \frac{11}{4}x^{4}y - \frac{11}{4}x^{2} y^{3} = \frac{11}{4} * (-2)^{4} * (-1) - \frac{11}{4} * (-2)^{2} * (-1)^{3} = -\frac{11}{2^{2} } * 2^{4} + \frac{11}{2^{2} } * 1 = -11 * 2^{2} +11 = -11 *4 + 11 = -44 +11 = -33[/tex]
