Question

Solve 2x-3/y=12 and 5x+7y=1

Answer 1

// Solve equation [2] for the variable  x  

 

 [2]    5x = 4y - 7

 [2]    x = 4y/5 - 7/5

// Plug this in for variable  x  in equation [1]

  [1]    2•(4y/5-7/5) - 3y = 12

  [1]     - 7y/5 = 74/5

  [1]     - 7y = 74

// Solve equation [1] for the variable  y  

  [1]    7y = - 74  

  [1]    y = - 74/7  

// By now we know this much :

   x = 4y/5-7/5

   y = -74/7

// Use the  y  value to solve for  x  

   x = (4/5)(-74/7)-7/5 = -69/7 , -74/7}