Answer:
12
Explanation:
Assuming that KI is 15 units longs, we can set up an equation by using the equations given.
2x-15+2x-6=15 /simplify
4x-21=15 /+21
4x=36 /÷ 4
x=9
Now that we know that x is 9 units, we plug it into the given equation of the line.
2*9-6=12
Thus, JI is 12 units long.
I hope this helps!