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A store received a delivery that consists of x boxes that weigh 30 pounds each and y boxes that weigh 20 pounds each. There are 64 total boxes in the delivery and they have a combined weight of 1400 pounds.


enter the number of boxes in the delivery that weigh 20 pounds.

Respuesta :

Let the number of 30 pound boxes represented by =x

Let the number of 20 pound boxes be represented by =y

As given, there are 64 boxes so equation is:

[tex]x+y=64[/tex] or [tex]x=64-y[/tex]  ..... (1)

Total weight is 1400 pounds so equation becomes

[tex]30x+20y=1400[/tex]  ...............(2)

Plug in the value of [tex]x=64-y[/tex] in 2nd equation

[tex]30(64-y)+20y=1400[/tex]

[tex]1920-30y+20y=1400[/tex]

[tex]10y=520[/tex]

[tex]y=52[/tex] and [tex]x=64-52=12[/tex]

Hence, the number of boxes for delivery that weigh 20 pounds is 52.