Answer:
The identity property of multiplication, also called the multiplication property of one says that a number does not change when that number is multiplied by 1. Ex. 12x1=12
 
        
                    
             
        
        
        
5x - 2x = 63 + 57
3x = 120
x = 40
        
             
        
        
        
Answer:
10 = 2y + 4
6 = 2y
y = 3
Step-by-step explanation:
18 = 10 + 2x
8 = 2x
x = 4
 
        
             
        
        
        
The straight edge of the semicircle is 4 units, as this is this the diameter.
The circumference of the full circle is 
C = pi*d = pi*4 = 4pi
which is the distance around the full circle (aka circle's perimeter)
So half of this is 4pi/2 = 2pi
Add this onto the straight edge length to get 4+2pi as the exact distance around the entire semicircle. This includes both straight and curved portions.
If you use the approximation pi = 3.14, then 4+2*pi = 4+2*3.14 = 10.28 is the approximate answer. To get a more accurate answer, use more decimal digits in pi.
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In summary,
exact answer in terms of pi is  4+2pi units
approximate answer is roughly 10.28 units  (using pi = 3.14)
 
        
             
        
        
        
Take out common factor, 3 :
3x - 3 = 3(x - 1)
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Answer: 3(x - 1)
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