\[\boxed{\mathbf{48}.}\]
\[\textbf{а)}\ f(x) = x^{3};\]
\[F(x) = \frac{x^{4}}{4};\]
\[\int_{0}^{1}{x^{3}\text{dx}} = F(1) - F(0) =\]
\[= \frac{1^{4}}{4} - \frac{0^{4}}{4} = \frac{1}{4}.\]
\[\textbf{б)}\ f(x) = x^{3};\]
\[F(x) = \frac{x^{4}}{4};\]
\[\int_{- 1}^{1}{x^{3}\text{dx}} = F(1) - F( - 1) =\]
\[= \frac{1^{4}}{4} - \frac{( - 1)^{4}}{4} = 0.\]
\[\textbf{в)}\ f(x) = x^{3};\]
\[F(x) = \frac{x^{4}}{4};\]
\[\int_{2}^{3}{x^{3}\text{dx}} = F(3) - F(2) =\]
\[= \frac{3^{4}}{4} - \frac{2^{4}}{4} = \frac{81}{4} - \frac{16}{4} = \frac{65}{4} =\]
\[= 16,25.\]