41
Step-by-step explanation:
Step 1:
Given DE = GF,
HJ = 3x + 20
JI = 15x - 64
Step 2 :
When 2 chords of a circle are same in length, then their distance from the center will be equal.
JI and HJ are the chord's length from the center because they are the perpendicular lines which joins the circle's center to the chord.
Hence we have, HJ = JI
=> 3x + 20 = 15 x - 64
=> 12 x = 84 => x = 7
To find JI, substitute the value we got for x in the expression for JI
Therefore JI = 15x - 64 = 15 * 7 - 64 = 41
