36, because the square root of 4 is 2 and the square root of 81 is 9. You multiply those and then double it to get 36.
        
             
        
        
        
9xa is the common factor.
You can complete the statement by dividing the two terms of the expression of the left side by 9xa, and you will get: 
36x^3a + 45xa^2 = 9xa ( 4x^2 + 5a)
        
             
        
        
        
Answer:
1/2
Step-by-step explanation:
We only care about the third coin
we could get heads or tails on the third flip
P (third coin will be heads) = outcome heads / total 
                                             =1/2
 
        
                    
             
        
        
        
Answer:
question is not proper 
Step-by-step explanation:
question is 
 
        
             
        
        
        
Remark
Supplementary angles add up to 180o. 
Givens
<1 = 124
<2 = 2x + 4
I imagine you are looking for either x or <2. 
Equation
<1 + <2 = 180          Substitute the givens
124 + 2x + 4 = 180  Collect like terms on the left.
128 + 2x = 180         Subtract 128 from both sides
2x = 180 - 128          Collect like terms on the right   
2x = 52                     divide by 2
x = 52/2
x = 26 <<<<<<<<< answer
<1 = 124
<2 = 2x + 4 = 2*26 + 4
<2 = 52 + 4
<2 = 56  <<<<<<<< answer
We need choices if you want an exact answer.