a. X + 673 = 768

         X      = 768 – 673 

         X      = 95 

b. X : 7 = 427

    X      = 427 x 7

    X      = 2989

\(10+2\cdot x=4^5:4^3\)

\(\Rightarrow10+2\cdot x=4^{5-3}\)

\(\Rightarrow10+2\cdot x=4^2\)

\(\Rightarrow10+2\cdot x=16\)

\(\Rightarrow2\cdot x=16-10\)

\(\Rightarrow2\cdot x=6\)

\(\Rightarrow x=\dfrac{6}{2}=3\)

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\(2\cdot x-6^2:18=3\cdot2^2\)

\(\Rightarrow2\cdot x-36:18=12\)

\(\Rightarrow2\cdot x-2=12\)

\(\Rightarrow2\cdot x=12+2\)

\(\Rightarrow2\cdot x=14\)

\(\Rightarrow x=\dfrac{14}{2}=7\)

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\(70-5\cdot\left(x-3\right)=3\cdot2\)

\(\Rightarrow70-5\cdot\left(x-3\right)=6\)

\(\Rightarrow70-5x+15=6\)

\(\Rightarrow-5x+15=6-70\)

\(\Rightarrow-5x+15=64\)

\(\Rightarrow-5x=64-15\)

\(\Rightarrow-5x=49\)

\(\Rightarrow x=-\dfrac{49}{5}\)

2^x+2-2^x=768

=>2^xx2²-2^x=768

=>2^x(4-1)=768

=>2^x=768:3=256

=>2^x=2⁸

=>x=8

\(\Rightarrow\left(x+x+x+x\right)+\left(3,2+1,8+1,7+2,3\right)=25,2\)

\(\Rightarrow4x+9=25,2\)

\(\Rightarrow4x=16,2\Rightarrow x=4,05\)

\(\Leftrightarrow\dfrac{3\cdot2^{x+1}}{2^{x+3}}=40\\ \Leftrightarrow\dfrac{3}{2^2}=40\left(vô.lí\right)\Leftrightarrow x\in\varnothing\)

\(8.3^x+3.2^x-6^x=24\)

\(\Rightarrow8.3^x+3.2^x-6^x-24=0\)

\(\Rightarrow\left(8.3^x-2^x.3^x\right)-\left(24-3.2^x\right)=0\)

\(\Rightarrow3^x\left(8-2^x\right)-3\left(8-2^x\right)=0\Rightarrow\left(8-2^x\right)\left(3^x-3\right)=0\)

\(\Rightarrow\orbr{\begin{cases}2^x=8\\3^x=3\end{cases}\Rightarrow}\orbr{\begin{cases}x=3\\x=1\end{cases}}\)

X*3069=3069

X=3069/3069

X-1

X = 3069/3069

X = 1

k cho minh nha

ko biet

1/5.2^x+1/3.2^x.2=1/5.2^7+1/3.2^7.2

2x(1/5+1/3.2)=2^7(1/5+1/3.2)

=>2^x=2^7
=> x=7