ما هو التصرف الصحيح للمأمومين إذا ختم الإمام قراءته بآية فيها سجدة ثم ركع دون أن يسجد؟

The prostration of recitation (Sujud al-Tilawah) is a Sunnah (recommended act), not an obligation. Therefore, if the Imam omits it, there is no sin upon him, and the congregants must follow him and omit the prostration. Whoever prostrates intentionally, their prayer becomes invalid according to many scholars. However, if one prostrates out of forgetfulness, thinking that the Imam had prostrated, their prayer is valid, but they must return to a standing position, then bow, and continue to follow their Imam.