EXPLANATION
Given the right triangle, we can apply the Pythagorean Theorem in order to get the value of x:
[tex]\text{hypotenuse}^2=\text{leg}^2_1+\text{leg}^2_2[/tex]
Replacing terms:
[tex]9^2=x^2+1^2[/tex]
Computing the powers:
[tex]81=x^2+1[/tex]
Subtracting -1 to both sides:
[tex]81-1=x^2[/tex]
Switching sides:
[tex]x^2=80[/tex]
Applying the squared root to both sides:
[tex]x=\sqrt[]{80}[/tex]
Simplifying:
[tex]x=4\sqrt[]{5}[/tex]
