Answer:
x=5
Step-by-step explanation:
Since this is a right triangle, we can use the Pythagorean theorem
a^2 +b^2 = c^2 where a and b are the legs and c is the hypotenuse
12^2 +x^2 = 13^2
144 +x^2 = 169
Subtract 144 from each side
144-144 +x^2 = 169-144
x^2 =25
Take the square root of each side
sqrt(x^2) = sqrt(25)
x = 5
