Answer:
14s^4-7s^2+15
Step-by-step explanation:
At the beginning the only bracket that is changing is the 3rd one because of the minus. (12s^4-6s^2+4s)+(6s^4-4s+27)-4s^4+s^2+12 then open the rest of the brackets. And start calculating.i will just to show you which ones u calculate together. (I'll separate the numbers depending on what they're squared to). 
12s^4+6s^4-4s^4=14s^4
-6s^2-s^2=7s^2
27-12=15
All together is 14s^4-7s^2+15
 
        
             
        
        
        
Answer:
2:9
Step-by-step explanation:
 
        
             
        
        
        
Step-by-step explanation:
Sum of interior angles of a polygon is given by (n-2)180°
where,n is the number of sides.
 Since this polygon has 5sides, 
sum of the interior angles = (5-2)180°=540°
 x+150°+120°+75°+60°=540°
x°=540°-405° = 135°
 
        
             
        
        
        
3525 is your answer please consider brainliest<3
        
             
        
        
        
R in this equation refers to the radius
