Solve the following system: y = x + 3 2x + y = 9

{y,x}={5,2}

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Step by Step Solution:

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System of Linear Equations entered :

 [1]           y-x=3

 [2]           2x+y=9

Equations Simplified or Rearranged :

  [1]    y - x = 3

  [2]    y + 2x = 9

Graphic Representation of the Equations :

   x + y = 3        2x + y = 9  

Solve by Substitution :

// Solve equation [2] for the variable  y

 [2]    y = -2x + 9

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

  [1]    (-2x+9) - x = 3

  [1]     - 3x = -6

// Solve equation [1] for the variable  x

  [1]    3x = 6

  [1]    x = 2

// By now we know this much :

   y = -2x+9

   x = 2

Solution :

{y,x} = {5,2}

the formula of a slope:

from a table we have

substitute:

the slope of f(x) is -1.

the graph of funcfion g(x) is a horizontal line. the slope of a horizontal line is equal 0. therefore the slope of g(x) is 0.

-1 < 0