There are 2 methods you are taught in Middle School.
Elimination and Substitution.
Answer:
Step-by-step explanation:
Order is impotant since you could easily make a positve number negative and vice versa. You switch the order of 5 subtracted by y to y-5.
Burma,Liberia<span> and the </span><span>United States</span>
Made by desmos graphing calculator
![\bf \textit{sum of all interior angles in a polygon}\\\\ n\theta = 180(n-2)~~ \begin{cases} n = sides\\ \theta =angle~in\\ \qquad degrees\\[-0.5em] \hrulefill\\ n= 100 \end{cases}\implies \theta 100=180(100-2) \\\\\\ 100\theta = 180(98)\implies 100\theta =17640\implies \theta =\cfrac{17640}{100}\implies \theta = \cfrac{882}{5}](https://tex.z-dn.net/?f=%5Cbf%20%5Ctextit%7Bsum%20of%20all%20interior%20angles%20in%20a%20polygon%7D%5C%5C%5C%5C%20n%5Ctheta%20%3D%20180%28n-2%29~~%20%5Cbegin%7Bcases%7D%20n%20%3D%20sides%5C%5C%20%5Ctheta%20%3Dangle~in%5C%5C%20%5Cqquad%20degrees%5C%5C%5B-0.5em%5D%20%5Chrulefill%5C%5C%20n%3D%20100%20%5Cend%7Bcases%7D%5Cimplies%20%5Ctheta%20100%3D180%28100-2%29%20%5C%5C%5C%5C%5C%5C%20100%5Ctheta%20%3D%20180%2898%29%5Cimplies%20100%5Ctheta%20%3D17640%5Cimplies%20%5Ctheta%20%3D%5Ccfrac%7B17640%7D%7B100%7D%5Cimplies%20%5Ctheta%20%3D%20%5Ccfrac%7B882%7D%7B5%7D)
which is pretty much just 176.4°, well, we also know that θ = 3x + 26.4
