Chapter 5.4, Problem 26MS

Here we celebrate the power of algebra as a powerful way of finding unknown quantities by naming them, of expressing infinitely many relationships and connections clearly and succinetly, and of uncovering pattern and structure.

Two temps. At midnight last night, points A and B on the surface of Earth had exactly the same temperature and barometric pressure. If we treat the values of T and P as numbers without units, the values satisfy the equations $T+P=91.80$ and $T-P=\mathrm{32.20.}$

Find the values of T and P.