Answer:
Simply put, algebra is about finding the unknown or putting real life variables into equations and then solving them. ... Algebra can include real numbers, complex numbers, matrices, vectors, and many more forms of mathematic representation
Step-by-step explanation:
 
        
             
        
        
        
Answer: option D
Step-by-step explanation:
 Remember the cosine identity:
 
 Given the right triangle DFE shown in the image, you can identify that the adjacent side and the hypotenuse for the angle F of this triangle are:
 
 Now you can substitute values into   and then reduce the fraction.
 and then reduce the fraction.
 THerefore you get:
 
        
                    
             
        
        
        
Answer:
144.78 cm
Step-by-step explanation:
57 times 2.54