Bài 2 tìm x a,4.(7x-3)=4mũ3+2mũ3 b,(24+5/x-1/).7mũ3=7mũ5 c,/x-5/=3 d,2mũ x=16

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1. Giải thích các bước giải:

   `a)`
   `4.(7x-3)=4^3+2^3`
   `=>4.(7x-3)=64+8`
   `=>4.(7x-3)=72`
   `=>7x-3=18`
   `=>7x=21`
   `=>x=21:7`
   `=>x=3`
   `b)`
   `(24+5|x-1|).7^3=7^5`
   `=>(24+5|x-1|)=7^2`
   `=>(24+5|x-1|)=49`
   `=>5|x-1|=25`
   `=>|x-1|=25:5`
   `=>|x-1|=5`
   `=>`\(\left[ \begin{array}{l}x-1=5\\x-1=-5\end{array} \right.\) 
   `=>`\(\left[ \begin{array}{l}x=6\\x=-4\end{array} \right.\) 
   `c)`
   `|x-5|=3`
   `=>`\(\left[ \begin{array}{l}x-5=3\\x-5=-3\end{array} \right.\) 
   `=>`\(\left[ \begin{array}{l}x=3+5\\x=-3+5\end{array} \right.\) 
   `=>`\(\left[ \begin{array}{l}x=8\\x=2\end{array} \right.\) 
   `d)`
   `2^x=16`
   `=>2^x=2^4`
   `=>x=4`

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2. $a)4(7x-3)=4^3+2^3$

   $4(7x-3)=64+8$

   $7x-3=72:4$

   $7x=18+3$

   $x=21:7$

   $x=3$

   $b)(24+5|x-1|).7^3=7^5$

   $24+5|x-1|=7^5:7^3$

   $5|x-1|=49-24$

   $|x-1|=25:5$

   $x=5+1$

   $x=6$

   $x=(-5)+1$

   $x=-4$

   \(\left[ \begin{array}{l}x=6\\x=-4\end{array} \right.\)

   $c)|x-5|=3$

   $x=3+5$

   $x=8$

   $x=(-3)+5$

   $x=2$

   \(\left[ \begin{array}{l}x=2\\x=8\end{array} \right.\)

   $d)2^x=16$

   $2^x=2^4$

   $2^{x+0}=2^4$

   $x=4-0$

   $x=4$

    

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