Vertices (s,t) Of
10 - 0.5 t = 5 - t = 20 - t
Equations are
a) t - 0.5t = -5, then t = -10
b) t - 0.5t = 10,. then t= 20
For point A) (0,10) IS a Vertice , because t= 10
Point B) IS NOT a Vertice
Point C) IS a Vertice, because t≥0
Point D) IS a Vertice, because of equation b) t - 0.5t = 10
Then answer is
OPTION B) (0,5) IS NOT a Vertice