Answer:
5-9i
Step-by-step explanation:
If you add the 4 and 1 you get 5, and if you add -7i and -2i since they are both negative, they stay negative, so you get -9i.  So the answer is 5-9i.
 
        
             
        
        
        
<em>1</em><em> </em><em>I </em><em>do </em><em>not </em><em>know</em>
<em>2</em><em> </em><em>t</em><em>h</em><em>i</em><em>s</em><em> </em><em>is </em><em>so </em><em>hard</em>
<em>3</em><em> </em><em>i</em><em> </em><em>don't </em><em>know</em><em> </em><em>what</em><em> </em><em>is </em><em>the </em><em>answer</em><em />
 
        
             
        
        
        
Answer is 
x > 5
Tell me if it helps
        
             
        
        
        
Answer:
3 more students need to sign up
Step-by-step explanation:
Let the equal number of students in 9 teams be x.
Total number of signed up students = 690.
Let t be the required number of students to be signed.
Therefore, 9x = 690+t.
This means, 690+t is a multiple of 9.
The least value of t to make 690+t, a multiple of 9 is 3 and hence,

= 77
Hence, 3 more students need to sign up and each of the 9 teams consists of 77 students.
 
        
             
        
        
        
Answer:
1,860 per minute and 111,600 per hour