280-x-140:35=270 1900-2x:35-32=16 720:41-2x-5=23.5 2^2x-1:4=8^3 x+2^5=2^10 -x+31-39=-69 -121-35-x=50 17+x-352-400=-32 IxI-5=-1 Ix+2I-13=-1

0 bình luận về “280-x-140:35=270 1900-2x:35-32=16 720:41-2x-5=23.5 2^2x-1:4=8^3 x+2^5=2^10 -x+31-39=-69 -121-35-x=50 17+x-352-400=-32 IxI-5=-1 Ix+2I-13=-1”

1. Đáp án:

    

   Giải thích các bước giải:

   IxI-5=-1

   IxI    = (-1)+5

   IxI    = 4

   *IxI = 4 ⇒ x= -4

   *IxI= 4 ⇒ x=4

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2. Đáp án:

   a) 

   $280-x-140:35=270$

   $280-x-4=270$

   $x=280-4-270$

   $x=6$

   b)

   $1900-2x:35-32=16$

   $-2x:35=16-1900+32$

   $-2x:35=-1852$

   $-2x=-64820$

   $x=32410$

   c)

   $720:41-2x-5=23.5$

   $\dfrac{515}{41}-2x=115$

   $2x=-\dfrac{4200}{41}$

   $x=-\dfrac{2100}{41}$

   d)

   $2^{2x-1}:4=8^3$

   $2^{2x-1}=(2^3)^3.2^2$

   $2^{2x-1}=2^{11}$

   $2x-1=11$

   $x=6$

   e)

   $x+2^5=2^10$

   $x=2^{10}-2^5$

   $x=992$

   f)

   $-x+31-39=-69$

   $-x=-69-31+39$

   $-x=-61$

   $x=61$

   g)

   $-121-35-x=50$

   $-x=50+121+35$

   $-x=206$

   $x=-206$

   h)

   $17+x-352-400=-32$

   $x=-32-17+352+400$

   $x=703$

   i)

   $IxI-5=-1$

   $|x|=-1+5$

   $|x|=4$

   $x=4$ hoặc $x=-4$

   j)

   $Ix+2I-13=-1$

   $|x+2|=-1+13$

   $|x+2|=12$

   TH1: $x+2=12$

   $x=10$

   TH2: $x+2=-12$

   $x=-12-2$

   $x=-14$

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