Answer: 4 - 5 = 4 + (-5) = -1
Step-by-step explanation:  You have to make the 5 into a negative number using parenthesis and do the math.
 
        
                    
             
        
        
        
Let X = science homework.
Then math homework would be 3x ( three times as long).
Now you have math plus science = 64 minutes:
x  + 3x = 64
Combine like terms:
4x = 64
 Divide both sides by 4:
x = 64 / 4
x = 16
He spent 16 minutes on science and 48 minutes on math.
 
        
             
        
        
        
Answer:
<em>Your answer will be </em> <em> cups of popcorn.</em>
<em> cups of popcorn.</em>
Step-by-step explanation:
To find out how much the new bags hold, you need to find out the discount.


<em>We know that the discount is </em> <em>.</em>
<em>.</em>
<em>To figure out how much the new bags hold, subtract by the old bags.</em>

<em>The new bags hold 12 cups of popcorn. </em>