Question

1. Find the value of c and d if9c+2d = 54с+ 2d = 6c = 6 and d = 8​

Answer 1

Answer:

c = 6 and d = 8​,  I suspect you know the answer and just need to know how

     d is not 8

Step-by-step explanation:

Disclaimer the student needs to verify the solution for typos, algebra and calculations

9c + 2d = 54  

 с + 2d  =   6        I would multiply this equation by -1, then add both equations

                            I picked -1 to get rid of 2d terms but an easier way would

                            have been to just subtract the bottom eq from the top eq

-с - 2d  =   -6

9c + 2d = 54

(-c + 9c) + (-2d + 2d) = -6 + 54              add the like terms

    8c     +      0          =   48

                       8c      =   48

                        c = 6             as you said   but now solve for d using

     

   с + 2d  =   6    c = 6   solve for d

   6 + 2d  =   6               subtract 6 from both sides

   6  - 6 + 2d  =   6 - 6

       0   + 2d  =    0

                  d  =    0/2

                  d  =    0         not 8

9c + 2d =  54

 с + 2d  =   6    

--------------------    subtract

  8c      =   48

        c   =   6