Phần típ theo nè!
Câu 5: Tìm \(x\):
Đề bài : \(xxx\) - \(x
\) x 105 = 30
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Câu 6: Tìm \(x \):
a) \(x \) x 7 + \(x\) = 384.
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b) \( x\)\(x
\) - \(x\) x 2 = 378.
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Câu 7: Tìm số tự nhiên ab biết ab x 9 = 2ab :
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Câu 8: Viết biểu thức sau thành tích 2 thừa số:
Đề bài: ab + ab x 2 + ab x 4 + ab =
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-------- Còn nữa -------
a: \(80\times2,5-80\times1,25-80\)
\(=80\times\left(2,5-1,25-1\right)\)
\(=80\times\left(1,25-1\right)=80\times0,25=20\)
b: \(26,12\times3,5-26,12\times2,4-26,12\)
\(=26,12\times\left(3,5-2,4-1\right)\)
\(=26,12\times0,1=2,612\)