and eight equations. That allows you to substitute values for six of the variables, reduce the set of equations down to two, and eliminate all but two unknowns, :
50 = sympy.sqrt((40-x2)**2 + (25-y2)**2)
170 = sympy.sqrt((60-x2)**2 + (55-y2)**2)
I am pretty sure that you have to use sympy.sqrt and not math.sqrt for sympy to be able to solve these.
If that doesn’t help, I suggest you try squaring both sides of each equation, then try again.