Question

Whats the value of x? x = ___

Answer 1

Since this is a right triangle, you can utilize the Pythagorean Theorem.

$a^2+b^2=c^2$

In THIS scenario, your hypotenuse and one of your legs are given. Therefore,

a=?
b=12
c=13

Now, substitute those values into the Pythagorean theorem and simply solve for "a"

$a^2+b^2=c^2$
$a^2+(12)^2=(13)^2$
$a^2+(144)=(169)$
$a^2=(169)-(144)$
$a^2=25$
$\sqrt{a^2}= \sqrt{25}$
$a=+5, a=-5$

Remember that you cannot have a negative measure. You cannot have a length measure -5 units. Therefore, we can ONLY take the positive value.
$a=5$

Thank you and I hope this helped. 

Answer 2

Using the Pythagorean Theorem, 169-144 = 25
The square root of 25 is 5 so x= 5
Hope this helps!