Hi,
Following the rules of PEMDAS you first subtract in the parentheses. 
(5-2)=3
Then multiply the parentheses.
(3)(-6)=-18
Solve the exponent.
-4^2=16
Then you add -18 and 16 to get -2. 
So the answer is B.-2.
I hope this helps.
        
             
        
        
        
Answer:
- 37
Step-by-step explanation:
5 • 2 • ( - 4 ) + 6 ÷ 2
= 5 • 2 • ( - 4 ) + [ 6 ÷ 2 ]
= 10 • ( - 4 ) + 3
= - 40 + 3
= - 37
 
        
             
        
        
        
Two and one thirds will be located between 2 and 3.
hope this helps :)
        
             
        
        
        
Ok so this is a difference of 2 perfect squares
1=1^2
49c^2=(7c)^2
to factor you remember
a^2-b^2=(a+b)(a-b) so
1^2-(7c)^2=(1+7c)(1-7c)
        
             
        
        
        
270=2b + a 
420=2a + 3c (you have to use trial and error for this)
B = 120
A = 30
C = 120 
Just to check 
270 = (2x120) + 30 
420 = (2x30) + (3x120)