Answer:
x=12
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
9^2 + x^2 = 15^2
81 + x^2 = 225
Subtract 81 from each side
x^2 =225-81
x^2 =144
Take the square root of each side
sqrt(x^2) = sqrt(144)
x=12
