$2\mathrm{.}36$ A weighted summer circuit using an ideal op amp has

three inputs using $10-$k resistors and a feedback resistor of

$50$ k$.$ A signal v$1$ is connected to two of the inputs while a

signal v$2$ is connected to the third. Express vO in terms of v$1$

and v$2.$ If v$1$

$=1$ V and v$2$

$=1$ V$,$ what is vO$?$