Final answer:
The set C comprising real numbers between 100 and 1000 is written in set-builder notation as C = x , where x is a real number and ℝ is the set of all real numbers.
Step-by-step explanation:
To write the set C that consists of the set of real numbers between 100 and 1000 using set-builder notation, we use the following expression:
C = x
Here, 'x' represents any real number, and ℝ denotes the set of all real numbers. The vertical bar '|' stands for 'such that', and the inequality indicates that x is a real number greater than 100 and less than 1000. It's important to note that 100 and 1000 are not included in the set, as indicated by the strict inequality symbols '<'.