Answer: C) Cannot be done
Taking the square root of a negative number is not possible unless you involve complex numbers. If your teacher has not introduced that topic yet, then you just simply say "cannot be done" or something along those lines.
 
        
             
        
        
        
Answer:

Step-by-step explanation:
we know that
The formula of law of cosines is equal to

where
a, b and c are sides. C is the angle opposite side c
In this problem we have

 
 
substitute the given values






 
        
             
        
        
        
Answer:
30 grams
Step-by-step explanation:
half life is 60 days so every 60 days the amount 480 grams will be half 
in 240 days will decay  240 /60 = 4 times 
once 480 /2 = 240
twice 240 /2 = 120 
trice 120 / 2 = 60 
four times 60/2 = 30 grams will be left 
 
        
             
        
        
        
Calculating Total Cost. Multiply the cost of an item or service by the sales tax in order to find out the total cost. The equation looks like this: Item or service cost x sales tax (in decimal form) = total sales tax. Add the total sales tax to the Item or service cost to get your total cost. Multiply retail price by tax rate
Let's say you're buying a $100 item with a sales tax of 5%. Your math would be simply: [cost of the item] x [percentage as a decimal] = [sales tax]. That's $100 x .