Answer:1.5
Step-by-step explanation:
 
        
             
        
        
        
The answer to your question is 0.1
        
                    
             
        
        
        
Step-by-step explanation:
1) first eliminate constant(number without variable) you eliminate constant by doing the inverse operation(if constant is being added, then subtract)(if constant is being subtracted, then add it)
ex: if   x+9=32
subtract 9 from both sides to get rid of it
x=23
2) if there is another constant but this constant is being multiplied/divided then do the opposite operation to remove it
you could multiply by 3 on both sides:
x+9=69
x=60
 
        
             
        
        
        
Answer:
 (d).  
 
Step-by-step explanation:
sin² β + cos² β = 1 
cos (α + β) = cos α cos β - sin α sin β 
cos α = √(1 -  ) = 21 / 29
 ) = 21 / 29 
cos β = 12 / 13 
sin β = √(1 -  ) = 5 / 13
 ) = 5 / 13 
sin α = 20 / 29 
cos (α + β) =  ×
 ×  -
 -  ×
 ×  =
 =  
 
 
        
             
        
        
        
First let's review how to find the surface area of a rectangular prism. Since the opposite faces have the same area, we just need to find one of each pair of faces and multiply the result by 2.
One face in each pairs adds up to 6*4+2*4+2*6=24+8+12=44
Now we just need to multiply this by 2!
44*2=88 cm^2
I really hope my explanation helped, if there are any more question about this please ask me in the comments I will answer them.