The expression which is equivalent to the provided expression of variable x is,
[tex]\dfrac{1}{1000x^3}[/tex]
Equivalent expressions are the expression whose result is equal to the original expression, but the way of representation is different.
The given expression in the problem is,
[tex](10x)-3[/tex]
Let the equivalent expression of this expression is f(x). Thus,
[tex]f(x)=(10x)^{-3}[/tex]
The number, with negative power, can be written in the fraction of 1 with the same but positive power or exponent. Therefore,
[tex]f(x)=\dfrac{1}{(10x)^{3}}[/tex]
Solve it further as,
[tex]f(x)=\dfrac{1}{(10)^3(x)^{3}}\\f(x)=\dfrac{1}{1000x^3}[/tex]
Hence, the expression which is equivalent to the provided expression of variable x is,
[tex]\dfrac{1}{1000x^3}[/tex]
Learn more about the equivalent expression here;
https://brainly.com/question/2972832
