a) (x+15) : 5 + 22= 24 b) (x – 36 ) : 18 = 12 c) (x – 3) ^ 2 = 16 d) 3^2x-1 = 27 e) (2 + x) ^ 3 = 8 Mong mn giúp =)

0 bình luận về “a) (x+15) : 5 + 22= 24 b) (x – 36 ) : 18 = 12 c) (x – 3) ^ 2 = 16 d) 3^2x-1 = 27 e) (2 + x) ^ 3 = 8 Mong mn giúp =)”

1. a,(x+15):5+22=24

   ⇔(x+15) : 5    =2

   ⇔ x+15          =10

   ⇔x  = -5

   b.(x-36):18=12

   ⇔x-36=216

   ⇔x=252

   c.(x-3)²=16

   ⇔\(\left[ \begin{array}{l}x-3=4\\x-3=-4\end{array} \right.\) 

   ⇔\(\left[ \begin{array}{l}x=7\\x=-1\end{array} \right.\) 

   d.$3^{2x-1}$=27

   ⇔3³=27

   ⇒2x-1=3

   ⇔x=2

   e.(2+x)³=8

   ⇔(2+x)³=2³

   ⇒2+x=2

   ⇔x=0

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2. `(x+15) : 5 + 22= 24`

   `=> (x+15) : 5 = 2`

   `=> x + 15 = 10`

   `=> x = -5`

   `(x – 36 ) : 18 = 12`

   `=> x – 36 = 216`

   `=> x = 252`

   `(x – 3) ^ 2 = 16`

   `=> (x – 3) ^ 2 = 4^2`

   `=>` \(\left[ \begin{array}{l}x-3=4\\x-3=-4\end{array} \right.\) 

   `=>`  \(\left[ \begin{array}{l}x=7\\x=-1\end{array} \right.\) 

   `3^(2x-1) = 27`

   `=> 3^(2x-1) = 3^3`

   `=> 2x -1 = 3`

   `=> 2x = 4`

   `=> x = 2`

   `(2 + x) ^ 3 = 8`

   `=> (2 + x) ^ 3 = 2^3`

   `=> 2 + x = 2`

   `=> x = 0`

   (Chúc bạn học tốt)

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