Answer:
1) x = 15
Explanation:
We use the Pythagorean thm for these questions. Where a and b are the legs (So order doesn't matter), and where c is the hypotenuse
1)
a² + b² = c²
9² + 12² = x²
81 + 144 = x²
x² = 225
You square root each side so you can get rid of the exponent on x.
x = 15