It should be 13 since 13+8 = 21. 21-7 = 13
        
             
        
        
        
Answer:
$300
Explanation: 
$10(cost of 1 book) x 5(how many comes in packages) = 50 ( total cost of 1 package)
Mr. Swanson ordered 6 so...
$50 x 6 = $300
Mr. Swanson would have $50 let's over
        
             
        
        
        
Answer:
27.5 inches^2
Step-by-step explanation:
Area of a triangle = 

Plugging in the equation,

 
        
             
        
        
        
2/3+(-1/3)
2/3-1/3
1/3 
Your answer is 1/3