Hello,
we can simplify as below
[tex]\dfrac{(2p^3q^4)^4}{(-3q^5)^2}*\dfrac{9}{(4p^2q)^2}=\dfrac{2^4p^{12}q^{16}3^2}{3^2q^{10}4^2p^4q^2}=p^{12-4}q^{16-10-2}=p^{8}q^{4}=p^{a+b}q^{b-a}[/tex]
So it means that
8 = a+b
4 = b-a
8+4 = a+b+b-a=2b
2b = 12
b = 6
and a = 6 - 4 = 2
hope this helps
