Toán Lớp 7: $\frac{2x-1}{27}$=$\frac{3}{2x-1}$ tìm x hộ mik với
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Toán Lớp 7: $\frac{2x-1}{27}$=$\frac{3}{2x-1}$ tìm x hộ mik với
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Lời giải và giải thích chi tiết:
(2x-1)/27=3/(2x-1)
=>(2x-1)(2x-1)=3.27
=>(2x-1)^2=81
=>(2x-1)^2=9^2
TH1: 2x-1=9
=>2x=10
=>x=5
TH2: 2x-1=-9
=>2x=-8
=>x=-4
Vậy x∈{5;-4}
(2x – 1)/27 = 3/(2x – 1)
<=> (2x – 1) . (2x – 1) = 27 . 3
<=> (2x – 1)^2 = 81
<=> (2x – 1)^2 = (+-9)^2
=> \(\left[ \begin{array}{l}2x – 1 = 9\\2x – 1 = -9\end{array} \right.\)
=> \(\left[ \begin{array}{l}2x = 9 + 1\\2x = -9 + 1\end{array} \right.\)
=> \(\left[ \begin{array}{l}2x = 10\\2x = -8\end{array} \right.\)
=> \(\left[ \begin{array}{l}x = 10 : 2\\x = -8 : 2\end{array} \right.\)
=> \(\left[ \begin{array}{l}x = 5\\x = -4\end{array} \right.\)
Vậy: x ∈ {5; -4}