Tìm \(x\), biết:
\(\left( {x + 9} \right) + \left( {x - 8} \right) + \left( {x + 7} \right) + \left( {x - 6} \right) + \left( {x + 5} \right) + \left( {x - 4} \right) = 63,6\).
Câu 403065: Tìm \(x\), biết:
\(\left( {x + 9} \right) + \left( {x - 8} \right) + \left( {x + 7} \right) + \left( {x - 6} \right) + \left( {x + 5} \right) + \left( {x - 4} \right) = 63,6\).
A. \(x = 11,1\).
B. \(x = 10,1\).
C. \(x = 10,3\).
D. \(x = 10,2\).
Phá ngoặc, sau đó sử dụng tính chất của phép cộng và phép nhân để thu gọn rồi ta đi tìm thừa số chưa biết. Muốn tìm thừa số chưa biết ta lấy tích chia cho thừa số đã biết.
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Đáp án : B(3) bình luận (0) lời giải
Giải chi tiết:
\(\left( {x + 9} \right) + \left( {x - 8} \right) + \left( {x + 7} \right) + \left( {x - 6} \right) + \left( {x + 5} \right) + \left( {x - 4} \right) = 63,6\)
\(\begin{array}{l}\left( {x + x + x + x + x + x} \right) + \left( {9 - 8 + 7 - 6 + 5 - 4} \right) = 63,6\\\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,6 \times x\,\,\,\,\,\,\,\,\,\,\,\,\, + \,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,3\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\, = 63,6\\\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,6 \times x\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\, = 63,6 - 3\\\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,6 \times x\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\, = 60,6\\\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,x\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\, = 60,6:6\\\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,x\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\, = \,\,\,10,1\end{array}\)
Vậy \(x = 10,1\).
Lời giải sai Bình thường Khá hay Rất Hay
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