The app isn't letting me post the picture alone so this is just here so I can post the picture ;-;

  (x, y) = (0, -2248)

Step-by-step explanation:

Substitution

Substitute for y:

  300x -2248 = 350x -2248

  0 = 50x . . . . . . . . add 2248-300x to both sides

  x = 0

  y = 300·0 -2248

The solution is (x, y) = (0, -2248).

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Elimination

Subtract the first equation from the second.

  (y) -(y) = (350x -2248) -(300x -2248)

  0 = 50x

  x = 0

  y = 300·0 -2248

The solution is (x, y) = (0, -2248).

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Additional comment

If you think for a bit about what the graph looks like, you realize both lines cross at their y-intercept, (0, -2248). That point of intersection is the solution to the system of equations.

to find the perimeter of the rectangle this is the expression:

x-9+x-9+3x-4+3x-4=138

if we simplify it:

8x-26=138

remember, 138 is what it all adds up to

the length is 11.5cm

the width is 57.5cm

the area is 661.25cm^2

the answers might not be correct use at own risk