Answer:
b=-3
Step-by-step explanation:
753,249 - 575,388 = 159,861
i hope it's right :)
ANSWER
![-\frac{\sqrt[]{3}}{2}](https://tex.z-dn.net/?f=-%5Cfrac%7B%5Csqrt%5B%5D%7B3%7D%7D%7B2%7D)
EXPLANATION
Given

We can find cos 150 by using

recall that
![\begin{gathered} \cos 30=\frac{\sqrt[]{3}}{2} \\ \end{gathered}](https://tex.z-dn.net/?f=%5Cbegin%7Bgathered%7D%20%5Ccos%2030%3D%5Cfrac%7B%5Csqrt%5B%5D%7B3%7D%7D%7B2%7D%20%5C%5C%20%20%5Cend%7Bgathered%7D)
Hence,
![\begin{gathered} \cos 150=-\cos 30 \\ =-\frac{\sqrt[]{3}}{2} \\ \end{gathered}](https://tex.z-dn.net/?f=%5Cbegin%7Bgathered%7D%20%5Ccos%20150%3D-%5Ccos%2030%20%5C%5C%20%3D-%5Cfrac%7B%5Csqrt%5B%5D%7B3%7D%7D%7B2%7D%20%5C%5C%20%20%5Cend%7Bgathered%7D)
Therefore, the value of cos 150 is
![-\frac{\sqrt[]{3}}{2}](https://tex.z-dn.net/?f=-%5Cfrac%7B%5Csqrt%5B%5D%7B3%7D%7D%7B2%7D)
- 18
2- 20
= -18
Because you do the same thing just going to end up with a negative.
Quotient means divide, so the expression would be r/3, I believe
hope it helps