{18sm[(461,5sm-8x)÷24,1]-120sm}÷150sm=1

{[(18•461,5-18•8x):24,1]-120}÷150=1

[(8307-144x):24,1]-120=150

(8307-144x):24.1=270

8307-144x=6507

144x=1800

x=12,5sm ve ya 125 mm.