Answer:
5
Explanation:
Let the number equal x. Half the number is then 
x
2
 and the reciprocal of that is 
2
x
The reciprocal of the number is 
1
x
 and half that is 
1
2
x
then 
2
x
+
1
2
x
=
1
2
4
x
+
x
2
x
2
=
1
2
10
x
=
2
x
2
2
x
2
−
10
x
=
0
2
x
(
x
−
5
)
=
0
Zero is not viable solution as its reciprocal is infinity. The answer is therefore 
x
=
5
 
        
             
        
        
        
0.1 repeating as a fraction is 1/9
        
             
        
        
        
The answer would be 1.40. The 3 significant figure are 1.39 and it wants us to round so we look at the 8 in 1.3981 and since 8 > 5 we know to round up.
        
             
        
        
        
The answer is (3x^2 - x +2 )= to AC
Area = 1/2 |BD| |AC|
(9x^3 - 3x^2 + 6x) = 1/2 (AC) 6x 
3x ( 3x^2 - x +2 )= 1/2 (AC) 2(3x) 
3^2 - x +2 = AC