Yes the first choice is the right choice.
Remember that the 3rd root range is from -infinity to infinity.
Answer:
The length of BC = 12
Step-by-step explanation:
c^2 = a^2 + b^2
15^2 = 9^2 + b^2
225 = 81 + b^2
b^2 = 225 - 81
b^2 = 144
b = 12
The length of BC is 12