% Ecuación 1
$$
\int_a^b f'(x)dx = f(b) - f(a)
$$

% Ecuación 2
$$
t' = t \frac{1}{\sqrt{1 - \frac{v^2}{c^2}}}
$$

% Ecuación 3
$$
\Big[
    M \frac{\partial}{\partial M} +
    \beta(g) \frac{\partial}{\partial g} +
    \eta \gamma
\Big]
G^n(x_1, x_2, \dots, x_n; M, g) = 0
$$

% Ecuación 4
$$
R_{00} \approx
    -\frac{1}{2}
    \sum_i
    \frac{\partial^2 h_{00}}{\partial(x^i)^2}
    =
    \frac{4\pi G}{c^2}
    (\rho c^2)
    \Rightarrow
    \bigtriangledown^2 \phi_g
    =
    4\pi G \rho
$$
