Answer:
45
Step-by-step explanation:

ssubstitute a and b for any of the numbers (3 or 6) and get 36+9 which is 45
45 = 

so you would need to find the square root to get c
 
        
             
        
        
        
Answer:
2:3
Step-by-step explanation:
A total of 30 students with 12 girls so its 12/30 & its the balance of 18 boys or 18/30
12:18 ÷ by 2 on both sides is.6:9 & 2:3, Answer is Ratio of 2:3.
 
        
             
        
        
        
Answer:
Step-by-step explanation:
-5x+31+3x=3
move everthing to one side
-5+31+3x-3=0
add and subtract common terms
-2x+28=0
divide across by common denominator
-x+14=0
Solve for x
x=14
 
        
             
        
        
        
Answer: 45/8 or 5 5/8
Step-by-step explanation:
9   5 = 45
1    8 = 8
45/8=5 and 5/8