0.85 is between 0.8 and 0.9
Start by decomposing the number inside the root into primes
Then group the terms into cubes if possible

rewrite the root
![\sqrt[3]{80}=\sqrt[3]{10\cdot2^3}](https://tex.z-dn.net/?f=%5Csqrt%5B3%5D%7B80%7D%3D%5Csqrt%5B3%5D%7B10%5Ccdot2%5E3%7D)
then cancel the terms that are cubes and bring them out of the root
Answer:
-5
Step-by-step explanation:
from graph
I think you will have t use theorem
Ba=Rv^2+vo^2
Ba=4^2+7^2
Ba=16+49
Ba=65