Answer:
Firstly, rewrite the equation:
⅓ (18 + 27) = 81
Substitute x for the given number of it's supposed equivalent.
In this case x = 12.
⅓ (18(12) + 27) = 81
Solve using PEMDAS and simplify what is in the parenthesis first. Then, multiply.
(18 x 12) + 27 = 243
Now, solving using PEMDAS, multiply the total of what you got that was originally in the parenthesis by ⅓ .
⅓ (243) = 81
When you multiple these number they are equivalent to 81.
81 = 81
Since the equation given, when substituted x for 12, is equivalent to 81, this proves that substituting x for 12 makes this equation true. 
 
 
        
             
        
        
        
Answer:
20
Step-by-step explanation:
 
        
                    
             
        
        
        

This can be considered as a very easy Question where you have to find the value of √85 and √86 upto 2 decimal places then we could find it easily.
Let's start!
Value of √85=9.21
Value of √86=9.27
Now it is obvious that 9.25 lies between √85 and √86.

What are rational no.?
Any pair of numbers which is in the form of p/q where p and q are integers and p and q are co-prime is called rational number.
 
        
                    
             
        
        
        
Answer:
∠ADB≅∠ABC by the Alternate Interior Angles Theorem
∠CAD≅∠ACB by the Alternate Interior Angles Theorem
∠BAD and ∠ADV are supplementary by the Consecutive Interior Angle Theorem
∠ABC and ∠BCD are supplementary by the Consecutive Interior Angle Theorem