Step-by-step explanation:
what is so special about 13 ?
the other problems you understand and can do ?
and then you don't understand 13 ?
that is really strange.
anyway, remember, when dividing by a term with exponent we subtract that exponent.
in other words we have
5/2 × x^(-3 - -6) = 5/2 × x^(-3 + 6) = 5/2 × x³ = 5x³/2
