My best guess would be 720.
My work: 30 x 12 = 360 
360 x 2 = 720
Hope this helps! If its not right please inform me on what I did wrong! 
 
        
             
        
        
        
Answer: +42x
Step-by-step explanation:
The student only multiplied each term individually. 
He should have (7x+3)² = (7x+3)(7x+3)
Which is 49x²+42x+9
Therefore the error is (42x) or the failure to apply the law of multiplication of variables in a bracket.
 
        
             
        
        
        
Answer:A, 1/1000
Step-by-step explanation:
10 times -10 is -100. -100 times -10 is 1,000
 
        
                    
             
        
        
        
Answer:
$20.15
Step-by-step explanation:
Given data
Original cost =  $9.57
Markup= 95%
Let us find the new cost of the basket
=95/100*9.57
=0.95*9.57
=$9.0915
Hence the cost of the basket is
= 9.57+9.0915
=18.66
Also, the sales tax is 8%
=8/100*18.66
=0.08*18.66
=1.4928
Therefore, the total amount to be paid is 
=18.66+1.4928
=$20.15
 
        
             
        
        
        
Answer:
We need to know the other marbles in the bag and how many there are of each.