Question

I posted the question in two halves that go together.

Answer 1

Looking at the diagram, we were told that angle QPs is equivalent to angle TPR

Also,

angle SPR + angle SPT = angle TPR

angle SPR = angle TPR - angle SPT

Again,

angle QPR + angle SPR = angle QPS

angle SPR = angle QPS - angle QPR

Therefore,

angle TPR - angle SPT = angle QPS - angle QPR