Question

find:-
${x}^{p - q} \times {x}^{q - p}$

Answer 1

=x^(p-q)×x^(q-p)
=x^(p-q+q-p)
=x^0
=1

Answer 2

${x}^{a} \times {x}^{b} = {x}^{a + b}$
so

${x}^{p - q} \times {x}^{q - p} = {x}^{p - q \: + \: q - p}$
which equals to
${x}^{0} = 1$