Answer:hello the answer is C. 7$
Step-by-step explanation:
 
        
             
        
        
        
Since the base is 3 inches and the height is 4 inches, as well as the area of a triangle being base*height/2, we get 3*4/2=6 in. for each triangle. Since we need 20 pieces for each puzzle, we multiply 6 by 20 to get 120. In addition, since 80 puzzles are needed, with 20 pieces for each puzzle, we have 120 inches for each puzzle and 120*80 = 9600 square inches of wood used
        
                    
             
        
        
        
Answer:
2
Step-by-step explanation:
 
        
                    
             
        
        
        
Remember distributive property
a(b+c)=ab+ac
we can ervers it
6(31)+6(4)-6(15)=6(31)+6(4)+6(-15)=6(31+4-15)=6(20)=120