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What is the solution of the system?
5x+6y=20
9x+11y=32

•(28, -20)
•(28, 20)
•(-28, 20)
•(20, -28)

Respuesta :

Answer:

The correct option is 1.

Step-by-step explanation:

The system of equations is

[tex]5x+6y=20[/tex]           ....(1)

[tex]9x+11y=32[/tex]          ....(2)

Multiply equation (1) by 11.

[tex]55x+66y=220[/tex]           ....(3)

Multiply equation (2) by 6.

[tex]54x+66y=192[/tex]           ....(4)

Subtract equation (4) from equation (3).

[tex]55x+66y-54x-66y=220-192[/tex]

[tex]x=28[/tex]

Substitute x=28 in equation (1).

[tex]5(28)+6y=20[/tex]

[tex]140+6y=20[/tex]

[tex]6y=-120[/tex]

[tex]y=-20[/tex]

Therefore the solution of the given system of equations is (28,-20). Option 1 is correct.