Answer:
1
Step-by-step explanation:
Use the Pythagorean theorem:
[tex]leg^2+leg^2=hypotenuse^2[/tex]
We have
[tex]leg=3,\ leg=x,\ hypotenuse=\sqrt{10}[/tex]
Substitute:
[tex]3^2+x^2=(\sqrt{10})^2[/tex]
[tex]9+x^2=10[/tex] subtract 9 from both sides
[tex]9-9+x^2=10-9[/tex]
[tex]x^2=1\to x=\sqrt1\\\\x=1[/tex]
