Step-by-step explanation:
first you do 3×1 get your answer and then × it by 2 then your answer you get you × it by 3 what you get - by 2 what you get you - by 1 and you get your answer hope I helped
 
        
             
        
        
        
Answer:

Step-by-step explanation:
we know that
The volume of a cube is equal to

where
s is the side length of the cube
we have

substitute in the formula


Remember the power rule
 ----> multiply the exponents
 ----> multiply the exponents
so

 
        
                    
             
        
        
        
Answer:
x= square root of 130
Step-by-step explanation:
a^2+b^2=c^2
a=7 b=9 c=x
49+81=x^2
130=x^2
square root of 130=x
 
        
                    
             
        
        
        
Step-by-step answer:
Referring to the attached diagram, the resultant of two forces each with magnitude F and inclined to each other at 2a equals 
Ra = 2Fcos(a) ..............................(1)
Similarly, the resultant of two forces each with magnitude F and inclined to each other at 2b equals 
Rb = 2Fcos(b)..............................(2)
We are given that 
Ra = 2Rb  ....................................(3)
Substitute (1) & (2) in (3) gives
2Fcos(a) = 2(2Fcos(b))
Expand
2Fcos(a) = 4Fcos(b)
Simplify
cos(a) = 2 cos(b)   QED
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Have a nice day!