well, the triangle is an isosceles, so it twin sides, and the twin sides make twin angles, as we see by the tickmarks on A and C, meaning AB = BC.
![\bf x+4=3x-8\implies 4=2x-8\implies 12=2x\implies \cfrac{12}{2}=x\implies 6=x \\\\[-0.35em] \rule{34em}{0.25pt}\\\\ AC\implies x+4\implies 6+4\implies 10](https://tex.z-dn.net/?f=%5Cbf%20x%2B4%3D3x-8%5Cimplies%204%3D2x-8%5Cimplies%2012%3D2x%5Cimplies%20%5Ccfrac%7B12%7D%7B2%7D%3Dx%5Cimplies%206%3Dx%20%5C%5C%5C%5C%5B-0.35em%5D%20%5Crule%7B34em%7D%7B0.25pt%7D%5C%5C%5C%5C%20AC%5Cimplies%20x%2B4%5Cimplies%206%2B4%5Cimplies%2010)
Eighths and their multiples are common fractions which I recommend memorizing, but to actually solve this, you use the literal meaning of a fraction and divide 5 by 8. See the long-division below (it was surprisingly difficult to type, so I hope it helps!).
To round 0.625 to the nearest hundredth, we go to the second decimal place, which is 5, so we round up to 0.63.
So the answer is C because 25 people each from republican.