The Circuit Shown Below, Let Find the Thévenin Equivalent Voltage $\mathrm { V } _ { \text {th } }$

Essay

the circuit shown below, let $$\mathrm { I } _ { \mathrm { s } } = 1 \mathrm {~mA} , \mathrm { R } _ { 1 } = 12 \mathrm { k } \Omega , \mathrm { R } _ { 2 } = 20 \mathrm { k } \Omega , \mathrm { R } _ { 3 } = 5 \mathrm { k } \Omega \text {. }$$
Find the Thévenin equivalent voltage $\mathrm { V } _ { \text {th } }$ and the Thévenin equivalent resistance Rth between terminals $a$ and $b$ .