Solve({x^2-11==y, x+y==-9}, {x,y}) doesn't work

[yinhang]

Equations of 2 degree with 2 unknows, cannot work? Thank you!

[Axel Kramer]

With commit b332396 I made the following change:

Now the Solve() function in the first step computes a Gröbner basis. The result of the GrobnerBasis() is then used for the "old Solve()" function

>>> GroebnerBasis({x^2-11-y, x+y+9},{x,y})
{70+17*y+y^2,9+x+y}

>>> Solve({70+17*y+y^2==0,9+x+y==0},{x,y})
{{y->-10,x->1},{y->-7,x->-2}}