The perimeter of RSTU will be C.22m if you look at both of them u will see they are both the same and tell you how long the sides are,........hope i was right:))
The top part equals 1 because anything to the power of zero equals one. then for the second one bring every variable with a negative exponent to the top and leave the 2 at the bottom
The first reaction represented is a decomposition reaction due to the fact the bonded pair are being split apart.
The second equation is a single displacement because the B and C have switched places, which is the only change making it a single displacement. If there had been another bond and A had also moved, it would be double.
