The length of IK is the sum of the lengths of JK and IJ, then we can formulate the following equation:
IK = IJ + JK
By replacing x +6 for IK, 2x for JK and 5x for IJ, we get:
x + 6 = 2x + 5x
Combining like terms on the right:
x + 6 = 7x
Subtracting x from both sides:
6 = 6x
Dividing both sides by 6:
1 = x
x = 1
Then, x equals 1, by replacing 1 for x into JK = 2x, we get:
JK = 2×1 = 2
Then, JK equals 2