(7.8×10⁷)+(9.9×10⁷)
(7.8×10000000)+(9.9×10000000)
(78000000)+(99000000)
177000000
        
             
        
        
        
The absolute value is always positive, so the numbers would be 4 and 4. 
Those are two equal numbers so it is: equal to
Hope this helps. 
        
                    
             
        
        
        
20 cans in kilograms = 336 grams * 20 cans / 1000 = 6.72 kg
        
             
        
        
        
Answer:
A. (-13,-3)
Step-by-step explanation:
Solve the system of two equations:

From the second equation:

Substitute it into the first equation:

So,

The solution is (-13,-4)