In parallelogram JKLM , diagonals KM and JL meet at point N . The length of KM is equal to 5x+1 units. The length of NM is equal to 2x+9 units. What is the value of x?

1 answer

In a parallelogram, the diagonals bisect each other. Therefore, the length of diagonal KM is twice the length of segment NM.

Let’s denote the lengths mathematically. We have:

  • Length of \( KM = 5x + 1 \)
  • Length of \( NM = 2x + 9 \)

Since N is the midpoint of KM, we have:

\[ NM = \frac{1}{2} KM \]

Substituting the expressions for \( KM \) and \( NM \) into the equation gives:

\[ 2x + 9 = \frac{1}{2}(5x + 1) \]

To eliminate the fraction, multiply both sides by 2:

\[ 2(2x + 9) = 5x + 1 \]

Distributing on the left side:

\[ 4x + 18 = 5x + 1 \]

Now, let’s solve for \( x \). First, subtract \( 4x \) from both sides:

\[ 18 = 5x - 4x + 1 \]

This simplifies to:

\[ 18 = x + 1 \]

Now, subtract 1 from both sides:

\[ 17 = x \]

Thus, the value of \( x \) is:

\[ \boxed{17} \]