Solving systems of linear equations algbraically.

(3,-6)

Step-by-step explanation:

  [1]    x - 2y = 15

  [2]    2x + 4y = -18

Graphic Representation of the Equations :

   -2y + x = 15        4y + 2x = -18  

Solve by Substitution :

// Solve equation [1] for the variable  x

 [1]    x = 2y + 15

// Plug this in for variable  x  in equation [2]

  [2]    2•(2y+15) + 4y = -18

  [2]    8y = -48

// Solve equation [2] for the variable  y

  [2]    8y = - 48

  [2]    y = - 6

// By now we know this much :

   x = 2y+15

   y = -6

// Use the  y  value to solve for  x

   x = 2(-6)+15 = 3

Solution :

{x,y} = {3,-6}

step-by-step explanation:

to find if any function is an inverse of the other, put the first equation in as x in the next one. then simplify and solve. if at the end you get the statement y = x, then it is an inverse. if you get anything else, it is not.