Answer:
63 houses have been sold this year. 
Step-by-step explanation:
There are 81 houses in the community. If 7/9 are sold this year, then all you have to do is multiplication. 
In this case, you would multiply 81 by 7/9 to get your answer. 
81/1 x 7/9:
 Cancel out the 9 and the 81. Then the denominator will be 1 x 1 and the numerator would be 7 x 9. It would be 63 (7x9=63) over 1 (1x1=1) which is just 63. Make sure to include units. 
 
        
                    
             
        
        
        
Answer:
The complex number in the form of a + b i is 3/2 + i √3/2
Step-by-step explanation:
* Lets revise the complex number in Cartesian form and polar form
- The complex number in the Cartesian form is a + bi
-The complex number in the polar form is r(cosФ + i sinФ)
* Lets revise how we can find one from the other
- r² = a² + b² 
- tanФ = b/a
* Now lets solve the problem
∵ z = 3(cos 60° + i sin 60°)
∴ r = 3 and Ф = 60°
∵ cos 60° = 1/2
∵ sin 60 = √3/2
- Substitute these values in z
∴ z = 3(1/2 + i √3/2) ⇒ open the bracket
∴ z = 3/2 + i √3/2
* The complex number in the form of a + b i is 3/2 + i √3/2
 
        
                    
             
        
        
        
It would take just over 6 minutes assuming it takes him 2. 6 minutes to wax a single square inch somehow.
        
             
        
        
        
Answer:
7.35
Step-by-step explanation:
5 pounds -> 5.25
1 pound -> 1.05 
7 pounds-> 7.35
 
        
             
        
        
        
8.9 x 10^-5 in scientific notation