Sure, we invented those particular words. But the concepts still exist and are true, and if there was a living thing to observe or think about them and come up with their own words for it, it'd be just as true for them as us, and if no living thing existed, it'd still be true, even without the verbage existing.
That's exactly the point.
We invented mathematics but the underlying concepts, the forces of nature that underpin the universe, are still there and do not depend on mathematics at all.
From dictionary.com
math·e·mat·ics (mth-mtks)
n. (used with a sing. verb)
The study of the measurement, properties, and relationships of quantities and sets, using numbers and symbols.
mathematics (ˌmæθəˈmætɪks; ˌmæθˈmæt-)
n
1. (Mathematics) (functioning as singular) a group of related sciences, including algebra, geometry, and calculus, concerned with the study of number, quantity, shape, and space and their interrelationships by using a specialized notation
2. (Mathematics) (functioning as singular or plural) mathematical operations and processes involved in the solution of a problem or study of some scientific field
math•e•mat•ics (ˌmæθ əˈmæt ɪks)
n.
1. (used with a sing. v.) the systematic treatment of magnitude, relationships between figures and forms, and relations between quantities expressed symbolically.
2. (used with a sing. or pl. v.) mathematical procedures, operations, or properties.
mathematics (mth-mtks)
The study of the measurement, relationships, and properties of quantities and sets, using numbers and symbols. Arithmetic, algebra, geometry, and calculus are branches of mathematics.
Note every definition states the "study of" or "treatment of" or "science of" or "expressed".
Mathematics is the human invention used to define the underpinnings of the universe, not the underpinnings themselves. Essentially it is a language, a way of expressing something.