HJK is a straight line, wth J somewher between H and K and the length of HK = 22.
H <--- (X/4) ---> J <--- (3X - 4) ---> K
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Since we know that HK = 22, then we can write,
HK = HJ + JK
22 = X/4 + (3X - 4) (multiply both sides by 4)
88 = X + 12X - 16 (rearrange the expression)
13X = 104
X = 8