Question

An open box is made from a 40 -cm by 50-cm piece of tin by cutting a square from each corner and folding the edges. The area of the resulting base is 1344cm squared. What is the length of the sides of the squares?

Answer 1

Answer:

  4 cm

Step-by-step explanation:

If x is the length of the side of the square (in cm), then the area of the base is ...

  1344 = (40 -2x)(50 -2x)

  336 = (20 -x)(25 -x) . . . . . divide by 4

  336 = x^2 -45x +500

Subtracting 336 gives ...

  x^2 -45x +164 = 0

  (x -41)(x -4) = 0 . . . . . . . factor

  x = 4 . . . . . . . . the dimension must be less than 20

The length of the sides of the squares is 4 cm.

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A graphing calculator makes short work of it.