/x-5/=(-4)Thêm mủ 2 nữa nha tại mik ko bt vt
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Ta có: \(\dfrac{x-3}{x-2}-\dfrac{x-2}{x-4}=1\dfrac{5}{21}\)
\(\Leftrightarrow\dfrac{21\left(x-3\right)\left(x-4\right)}{21\left(x-2\right)\left(x-4\right)}-\dfrac{21\left(x-2\right)^2}{21\left(x-2\right)\left(x-4\right)}=\dfrac{26\left(x-2\right)\left(x-4\right)}{21\left(x-2\right)\left(x-4\right)}\)
\(\Leftrightarrow26\left(x^2-6x+8\right)=21\left(x^2-7x+12\right)-21\left(x^2-4x+4\right)\)
\(\Leftrightarrow26x^2-156x+208=21x^2-147x+252-21x^2+84x-84\)
\(\Leftrightarrow26x^2-156x+208+63x-168=0\)
\(\Leftrightarrow26x^2-93x+40=0\)
\(\text{Δ}=\left(-93\right)^2-4\cdot26\cdot40\)
\(=8649-4160\)
\(=4489\)
Vì Δ>0 nên phương trình có hai nghiệm phân biệt là:
\(\left\{{}\begin{matrix}x_1=\dfrac{93-67}{52}=\dfrac{1}{2}\left(nhận\right)\\x_2=\dfrac{93+67}{52}=\dfrac{40}{13}\left(nhận\right)\end{matrix}\right.\)
\(5\cdot x+x=150:2+3\)
\(x\cdot\left(5+1\right)=75+3\)
\(x\cdot6=78\)
\(x=78:6\)
\(x=13\)
\(2^x:2^5=1\)
\(2^{x-5}=2^0\)
\(\Rightarrow x-5=0\)
\(x=5\)
\(5x+x=150:2+3\)
\(\Rightarrow\) \(6x=78\)
\(\Rightarrow\) \(x=13\)
\(2^x:2^5=1\)
\(\Rightarrow\) \(2^{x-5}=1\)
\(\Rightarrow\) \(x-5=1\)
\(\Rightarrow\) \(x=6\)
\(a,\Rightarrow\left(35x+3\right)\cdot19=152\\ \Rightarrow35x+3=8\\ \Rightarrow x=\dfrac{1}{7}\\ b,\Rightarrow3\left(x+7\right)=42\\ \Rightarrow x+7=14\Rightarrow x=7\\ c,\Rightarrow3\left(x+1\right)=48\\ \Rightarrow x+1=16\Rightarrow x=15\\ d,\Rightarrow120-5x+100\cdot2:5=4\cdot15\\ \Rightarrow120-5x+40=60\\ \Rightarrow5x=100\Rightarrow x=20\\ e,\Rightarrow4x-10=30\\ \Rightarrow4x=40\\ \Rightarrow x=10\\ g,\Rightarrow10x+10=70\\ \Rightarrow10x=60\\ \Rightarrow x=6\)
\(2^x.4=32\)
\(2^x=8\)
\(2^x=2^3\)
\(\Rightarrow x=3\)
\(2^x.4=32\)
\(2^x=32:4\)
\(2^x=8=2^3\)
\(>>x=3\)
\(x^{15}=x^3\)
\(2^{15}=32^3\)
\(\left(2.x+1\right)^3=125\)
\(\left(2.x+1\right)^3=5^3\)
\(2.x+1=5\)
\(2.x=6\)
\(x=6:2=3\)
giúp mik nha
|x-5|=(-4)2
|x-5|=16
\(\Rightarrow\orbr{\begin{cases}x-5=16\\x-5=-16\end{cases}}\)
\(\Rightarrow\orbr{\begin{cases}x=16+5=21\\x=-16+5=-11\end{cases}}\)
Vậy x=21 hoặc x=-11