Answer:
x =12
Explanation:
We use the Pythagorean theorem
a^2 + b^2 =c^2 where a and b are the legs and c is the hypotenuse
x^2 + 5^2 = 13^2
x^2 +25 =169
Subtract 25 from each side
x^2 +25-25=169-25
x^2 = 144
Take the square root of each side
sqrt(x^2) = sqrt(144)
x = 12