You could use change of base formula
        
             
        
        
        
Answer: Unit price = 0.2 per ounce
Step-by-step explanation:
What we were given;
Product price = $4
Quantity of product = 20 ounce
To get the unit price of the strawberry jam,
We simply devide the product price by the quantity of the product 
Therefore;
Unit price = 4 / 20
Unit price = 0.2 per ounce
 
        
             
        
        
        
Answer:
 <em>(4). is the correct answer</em> 
Step-by-step explanation:
(- 3, 1, 1) 
(1). - 3 - 1 - 1 ≠ - 2  not an answer... 
(2). - 3 - 1 + 3(1) ≠ 2 not an answer... 
(3). 4( - 3) + 1 - 3(1) ≠ - 4 not an answer... 
<em>(4). 2(- 3) + 3(1) + 4(1) = 1 </em>
<em>3(1) + 3(1) = 6 </em>
<em>- 3 = - 3(1) </em>