x
3/10 *(-log(10) + log(3))
$$\left(\frac{3}{10}\right)^{x} \left(- \log{\left (10 \right )} + \log{\left (3 \right )}\right)$$
x 2
3/10 *(-log(10) + log(3))
$$\left(\frac{3}{10}\right)^{x} \left(- \log{\left (10 \right )} + \log{\left (3 \right )}\right)^{2}$$
x 3
3/10 *(-log(10) + log(3))
$$\left(\frac{3}{10}\right)^{x} \left(- \log{\left (10 \right )} + \log{\left (3 \right )}\right)^{3}$$