Answer:
(10x)²
Explanation:
For this equation, you can imagine it as 100×x².
If you want to put this all into the brackets, you must square root 100.
The square root of 100 is 10, so the equation can be written as 10²x².
This can be combined to (10x)².
**This question involves expanding and factorising simple algebraic equations with powers, which you may wish to revise. I'm always happy to help!