Answer:
[tex]\boxed {\boxed{\sf25}}[/tex]
Step-by-step explanation:
[tex]\sf \sqrt{313^2-312^2}[/tex]
[tex]\sf 313^2=97969[/tex]
[tex]\sf 312^2=97344[/tex]
[tex]\sf \sqrt{97969-97344}[/tex]
[tex]\sf 97969-97344=625[/tex]
[tex]\sf \sqrt{625}[/tex]
[tex]\sf 625=25^2[/tex]
[tex]\sf \sqrt{25^2}[/tex]
Apply radical rule:
[tex]\sf \sqrt{25^2}=25[/tex]