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toiconanglamchieu
2 năm trước
Thấu kính hội tụ có tiêu cự f (cm). Vật AB vuông góc với trục chính và cách thấu kính một đoạn d=60cm thì cho ảnh d' cách thấu kính là 180 cm. Hãy xác định tiêu cự f Em đang gấp Giúp em với ạ
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