Answer:
The answer of the first on is 15 b because to find the perimeter of 2d shapes we have to add all the sides given ex: 5+5+5=15 so the answer of first question if 15.
Step-by-step explanation:
 
        
                    
             
        
        
        
Answer:
3
1
2
Step-by-step explanation:
Step 1: Subtract 9
50.24 = 3.14x²
Step 2: Divide by 3.14
x² = 16
Step 3: Square root both sides
x = ±4
 
        
             
        
        
        
A=20
5a-4=3a+36 (subtract 3a from both sides and add 4 to both sides) 
2a=40. Divide 40by 2 
A=20
        
             
        
        
        
Answer:
x=0 and y=3
Step-by-step explanation:
If x=0, then we can just plug that value into the other equation and solve for y:
x+4y=12
0+4y=12
4y=12
y=3
Therefore, the solution to the system of equations is x=0 and y=3
 
        
                    
             
        
        
        
Step-by-step explanation: 
1. 3:4, 6:8, 9,12
So 12:15 is the same thing as 12/15 you need to simplify so 12 devided by 2 is 4 and 15 divided by 3  is 5 so question to is 4:5