I need help with the equation for math

Answer:
-12a^-5 or -12/a^5
Step-by-step explanation:
The rules of exponents apply:
(a^b)(a^c) = a^(b+c)
1/a^b = a^-b
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[tex]\dfrac{2}{3}a^{-2}b^{-1}\cdot -18a^{-3}b^1=\dfrac{2(-18)}{3}a^{-2-3}b^{-1+1}\\\\=-12a^{-5}b^0=-12a^{-5}\\\\=\dfrac{-12}{a^5}[/tex]