a) \(216:x-117:x+18:x=9\)
\(\dfrac{216}{x}-\dfrac{117}{x}+\dfrac{18}{x}=9\)
\(\dfrac{1}{x}.\left(216-117+18\right)=9\)
\(\dfrac{117}{x}=9\)
\(x=117:9=13\)
\(...\left(256-215\right).x=29643\)
\(41.x=29643\)
\(x=29643:41=723\)
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