Answer:
x = 12
Step-by-step explanation:
We can use the Pythagorean theorem to solve
a^2 +b^2 =c^2 where a and b are the legs and c is the hypotenuse
9^2 +x^2 = 15^2
81 +x^2 = 225
Subtract 81 from each side
81-81 +x^2 = 225-81
x^2 = 144
Take the square root of each side
sqrt(x^2) = sqrt(144)
x = 12
