Answer:
[tex]\dfrac{-20d^3t^2}{v^5}[/tex]
Step-by-step explanation:
The applicable rules of exponents are ...
(a^b)(a^c) = a^(b+c)
a^-b = 1/a^b
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[tex](4d^2t^5v^{-4})(-5dt^{-3}v^{-1})=(4)(-5)d^{(2+1)}t^{(5-3)}v^{(-4-1)}\\\\=\boxed{-20d^3t^2v^{-5}=\dfrac{-20d^3t^2}{v^5}}[/tex]
