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If LN = 7x - 27 and LM = 4x - 29, and MN = 5x - 9, find MN.

User Shekit
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1 Answer

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Final answer:

The problem involves finding the length of MN given algebraic expressions for segments LN, LM, and MN. Without further geometric context, MN = 5x - 9, where x is a variable. By assuming LN + LM = MN and solving for x, we find MN to be 30.5 units.

Step-by-step explanation:

The student is tasked with solving a problem involving the lengths of segments LN, LM, and MN, which are represented by linear expressions in terms of a variable x. To find the value of segment MN, it is essential to understand that in a geometrical context, especially in a triangle, the lengths of the sides must satisfy the triangle inequality theorem. This theorem states that the sum of the lengths of any two sides must be greater than the third side. Based on the expressions given for LN, LM, and MN, it is possible that these represent the sides of a triangle. However, since there is no explicit mention of a triangle or any geometric figures, we will solve it as a simple algebraic problem.

Using the information given:

  • LN = 7x - 27
  • LM = 4x - 29
  • MN = 5x - 9

One might attempt to solve this problem by adding the equations for LN and LM to obtain MN, as if using the properties of a triangle. However, without the explicit statement that these segments form a triangle, we cannot assume that LN + LM = MN. Since the problem only provides separate expressions for each segment, one way to solve for MN is to assume that the problem allows us to equate LN + LM to MN, under the assumption that these do indeed represent the sides of a triangle. In this case, the problem becomes:

(7x - 27) + (4x - 29) = 5x - 9

This simplifies to:

11x - 56 = 5x - 9

Which yields:

6x = 47

And therefore:

x = 47 / 6

Substituting this back into the expression for MN:

MN = 5x - 9 = 5(47 / 6) - 9

Which simplifies to:

MN = 39.5 - 9 = 30.5.

Therefore, the length of segment MN is 30.5 units.

User Michael Vehrs
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