Find the power supplied by $V_1$ given that $V_1 = 15 V$, $R_1 = 14 k\Omega$, $R_2 = 7 k\Omega$, $R_3 = 17 k\Omega$, $R_4 = 20 k\Omega$, $R_5 = 13 k\Omega$, and $R_6 = 8 k\Omega$.

$P =$ $mW$