Question

Solve the system using elimination. x − 4y = 4 and -3x − 4y = 12

Answer 1

  x - 4y = 4

-3x - 4y = 12

Subtract the first equation from the second

  x - 4y = 4

-4x      = 12

Divide the second equation by (-4)

  x - 4y = 4

  x      =  -3

Subtract the second equation from the first

   - 4y  =  7

  x      =  -3          

Divide the first equation by (-4)    

       y  =  -7/4

  x      =  -3        

So, the solution is  x = -3  and  y = - 7/4