Hi, I'm doing electrical systems and I have an issue with solving the simultaneous equations after nodal analysis. can someone please show me the steps, I know it's basic, but I'm pretty desperate.

(-2)((V1-Vth)/80)+((Vth-V1)/20)=0

((V1-24)/20)+((V1-Vth)/20)+((V1-4Vth)/80)=0

any help will be great thanks.