Answer: 1/6
Step-by-step explanation:
Since Sam has to memorize 1/2 of his lines and he memorizes 1/3 of his lines today, the fractions of his lines that he has left to memorize will be gotten by subtracting 1/3 from 1/2. This will be:
= 1/2 - 1/3
= 3/6 - 2/6
= 1/6
Therefore, he has 1/6 of his lines left to memorize. 
 
        
                    
             
        
        
        
Answer:
8 vertices
Step-by-step explanation:
Use Euler's Theorem: V-E+F=2
F=12
E=18
Thus, we have:
V-18+12=2
V-18=-10
V=8
So there are 8 vertices
 
        
             
        
        
        
Answer:
B
Step-by-step explanation:
x³ + y³ ← is a sum of cubes and factors in general as
x³ + y³ = (x + y)(x² - xy + y²)
with trinomial factor (x2 - xy + y2) → B