en.wikipedia.org/wiki/Proportionality_(mathematics)

In mathematics, two variables are proportional if there is always a constant ratio
between them. ... To express the statement "y is inversely proportional to x"
mathematically, we write an ... Formally, two variables are inversely proportional (
also called **varying inversely**, in inverse variation, in inverse proportion, in
reciprocal ...

www.sparknotes.com/math/algebra1/variation/section2.rhtml

The statement " y **varies inversely** as x **means** that when x increases, y decreases
by the same factor. In other words, the expression xy is constant: ...

www.khanacademy.org/math/algebra2/rational-expressions-equations-and-functions/direct-and-inverse-variation/v/direct-and-inverse-variation

Sal explains what it **means** for quantities to **vary** directly or **inversely**, and gives
many examples of both types of variation.

www.merriam-webster.com/dictionary/inversely

**Definition** of inversely. 1 :in an inverse order or manner. 2 :in the manner of
inverse variation. **varies inversely**. NEW! Time Traveler. First Known Use: 1660.

www.wyzant.com/resources/answers/37337/what_does_varies_indirectly_mean_in_math

For example, x and y vary indirectly **means** x*y is constant. ... The converse is y
**varies inversely** with x such as y=10/x where any increase in x ...

www.dictionary.com/browse/inverse

**Inverse definition**, reversed in position, order, direction, or tendency. See more.

www.varsitytutors.com/hotmath/hotmath_help/topics/inverse-variation

While direct variation describes a linear relationship between two variables,
inverse variation describes another kind of relationship. We say y **varies inversely**
...

www.varsitytutors.com/hotmath/hotmath_help/topics/direct-inverse-variation

Direct & Inverse Variation ... This **means** that as x increases, y increases and as x
decreases, ... We say y **varies inversely** with x (or as x , in some textbooks) if :.

www.mesacc.edu/~pikeu/mat120/notes/variation/inverse/inverse.html

Example 1 – If x **varies inverse** as y, and x = 7 when y = 3, find y when x = 9. ...
Inverse variation problems are solved using the equation Inverse . Step 1.