keep on getting error that .float64 has no callable rint attribute

Question

def solveNLEs(xyz0):
    def f(xyz):
        x=xyz[0]
        y=xyz[1]
        z=xyz[2]

        a=x**2 + y**2 - 10
        b=x*y + y*z**2 + 15
        c=y**2 + z -