Solving a system by resultant computations

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I want to solve the following system f(x,y,z)=g(x,y,z)=h(x,y,z)=0 in Sage using resultant computations, where f(x,y,z)=x^2 + y + z -1 and g(x,y,z)=x + y^2 + z-1 and h(x,y,z)=x^2 + y + z^2 -1. So what are sufficient commands to do this, and thank you.