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The length of a rectangle is equal to triple the width. Which system of equations can be used to find the dimensions of the rectangle if the perimeter is 86 centimeters

User Sethmr
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2 Answers

2 votes

Final answer:

To determine the rectangle's dimensions with a perimeter of 86 cm and a length three times its width, we use a system of equations. The width is calculated to be 10.75 cm and from there, we calculate the length to be 32.25 cm.

Step-by-step explanation:

To find the dimensions of a rectangle where the length is triple the width and the perimeter is 86 centimeters, we can set up a system of equations. Let's denote the width as w and the length as l. Since the length is equal to triple the width, we have l = 3w. The formula for perimeter P of a rectangle is given by P = 2l + 2w. Substituting the perimeter given and the relationship between length and width, we can write the equations as:

  • l = 3w
  • 2l + 2w = 86

By substituting the first equation into the second, we get:

  • 2(3w) + 2w = 86
  • 6w + 2w = 86
  • 8w = 86
  • w = 86 / 8
  • w = 10.75 cm

Then, using the first equation, we find the length:

  • l = 3(10.75)
  • l = 32.25 cm

Thus, the width is 10.75 centimeters, and the length is 32.25 centimeters.

User Pokuri
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6.1k points
3 votes

Answer:

w=10.75 l=32.25

Step-by-step explanation:

So if we know that the length is 3 times as long as the width than if the width is x, length would be 3x.

3x+3x+x+x=86 There are two lengths and two widths

8x=86 Combine like terms

x=10.75 divide both sides by 8 and our width is 10.75

Length is 32.25 multiply 10.75 by 3

User Amighty
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6.0k points