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NEED HELP ASAP!

Betsy buys three lamps and two end tables and pays $520. Her friend Tina buys two lamps
and RETURNS an end table and only pays $20. What do the lamps and end tables cost?

Respuesta :

sqdancefan

9514 1404 393

Answer:

  • lamp: $80
  • end table: $140

Step-by-step explanation:

If we let x and y represent the costs of a lamp and end table, respectively, the two purchases can be written as ...

  3x +2y = 520

  2x -y = 20

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These equations can be solved many ways. If we use "elimination", we can add twice the second equation to the first to eliminate y:

  (3x +2y) +2(2x -y) = (520) +2(20)

  7x = 560 . . . . simplify

  x = 80 . . . . . . divide by 7

  y = 2x -20 = 2(80) -20 = 140

The cost of a lamp is $80; the cost of an end table is $140.

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