Systems of equations - can someone please help me

Consider the reaction 2x2y2+z2⇌2x2y2z which has a rate law of rate= k[x2y2][z2] select a possible mechanism for the reaction.

The train station clock runs too fast and gains 5 minutes every 10 days. how many minutes and seconds will it have gained at the end of 9 days?

    choose the correct definition for  extremo.  a.  end      b.  extra      c.  extract      d.  eventual