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Lena has 2 boxes of buttons A and B.In total are 1.200 buttons .She move 360 buttons from box A to B.There are now 3 times as many buttons in box B than box A.Homany buttons were in box A at the start?

Respuesta :

znk

Answer:

660

Step-by-step explanation:

Let  A = number of buttons in Box A

and B = number of buttons in Box B

We have two conditions:

(1)            A + B = 1200

(2)       B + 360 = 3(A – 360)     Remove parentheses

          B + 360 = 3A - 1080      Subtract 360 from each side

(3)                 B = 3A - 1440       Substitute (3) into (1)

A + 3A - 1440 = 1200               Combine like terms

      4A - 1440 = 1200               Add 1440 to each side

                4A  = 2640               Divide each side by 4

                   A = 660

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