44 inches. 
All you have to do is find out what 10% of 40 is then add it back to 40. In the case of finding 10% of something you just “chop” of the back number (or move the decimal place forward) so 10% of 40 is 4. The. 40+4=44. 
You can also multiply fractions to find the percent of a number but that is not necessary in this case.
        
             
        
        
        
Answer:
20%
0.12
Step-by-step explanation:
Convert 1/5 to a percentage.
1/5 * 100% = 20%
Convert 12/100 to a decimal.
0.12
 
        
                    
             
        
        
        
7/36
Multiply the top together and then the bottom together and the final numbers on top and bottom is your answer.
        
                    
             
        
        
        
Combine like terms. 
4x^3 -6x^3= -2x^3
-8x^2 +2x^2= -6x^2
Answer = -2x^3 -6x^2 +4