You’d set up a proportion. I did 25/15=7x-40/18.
Then you would cross multiply to get 15(7x-40)=450
Distribute the 15.
105x-600=450
 Add 600 to both sides, so the -600 cancels out.
Then you’re left with 105x=1050
Divide both sides by 105 and you get x=10
        
             
        
        
        
 Answer with Step-by-step explanation:
We are given that 
We have to find the fourth roots of given complex number.

By using the formula 



Angle of rotation=
Therefore, the four roots of given complex number are




 
        
             
        
        
        
The product of a scalar and a matrix is found by multiplying each element of the matrix by the scalar. Multiply each element by -4.
... [4 -12 -24 12]
 
        
             
        
        
        
Answer:
45.1 km^2
hope this helps
have a good day :)
Step-by-step explanation: