What is the value of x? If necessary, round to the nearest tenth.

Answer:
8
Step-by-step explanation:
h²= p²+ b²
or, (9+x)² = 15²+x²
or, 81 + 18x + x² = 225 +x²
or, 18x = 225-81
or, 18x = 144
or, x= 144/18
x= 8