Question

Simplify (-5x^3)^-2 using only positive exponents

Answer 1

Hope you know that x^(-1) = 1/x  used this you get 

(-5x^3)^-2 = 1/(-5x^3)^2 = 1/{(-5^2)(x^6)} = 1/(25x^6)

hope helped 

Answer 2

$a^{-n}=\dfrac{1}{a^n}\\\\(a^n)^m=a^{n\cdot m}\\\\(a\cdot b)^n=a^n\cdot b^n\\------------------\\\\\left(-5x^3\right)^{-2}=\dfrac{1}{\left(-5x^3\right)^2}=\dfrac{1}{(-5)^2(x^3)^2}=\dfrac{1}{25x^{3\cdot2}}=\boxed{\dfrac{1}{25x^6}}$