Answer
$U_{total}=-6.34\times 10^{-10}J$
Work Step by Step
We can find the total potential energy of the system as follows:
$U_{total}=G(\frac{m_1m_2}{x_2-x_1}+\frac{m_1m_3}{x_3-x_1}+\frac{m_2m_3}{x_3-x_2})$
We plug in the known values to obtain:
$U_{total}=6.67\times 10^{-11}(\frac{(1.00)(2.00)}{1.00}+\frac{(1.00)(3.00)}{2.00}+\frac{(2.00)(3.00)}{1.00})$
$U_{total}=-6.34\times 10^{-10}J$
