Question

7x - 3y = 18
6x + 7y = 25​

Answer 1

Step-by-step explanation:

Solve by Substitution :

// Solve equation [2] for the variable  x 

 

[2] 7x = 3y + 18 [2] x = 3y/7 + 18/7

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

  [1] 6•(3y/7+18/7) - 7y = 25   [1] - 31y/7 = 67/7   [1] - 31y = 67

// Solve equation [1] for the variable  y 

  [1] 31y = - 67    [1] y = - 67/31 

// By now we know this much :

  x = 3y/7+18/7   y = -67/31

// Use the  y  value to solve for  x 

  x = (3/7)(-67/31)+18/7 = 51/31 

Solution :

 {x,y} = {51/31,-67/31} 

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