Tìm x: a, 461 + ( x-4) = 387 b, 11- ( – 53 + x) = 97 c, -( x+84 ) + 213 = -16 d, 3- ( 17-x) = 289 – ( 36 + 289) e, 25 – ( x+5 ) = 415 – ( 15 – 415)

0 bình luận về “Tìm x: a, 461 + ( x-4) = 387 b, 11- ( – 53 + x) = 97 c, -( x+84 ) + 213 = -16 d, 3- ( 17-x) = 289 – ( 36 + 289) e, 25 – ( x+5 ) = 415 – ( 15 – 415)”

1. `a)461 + ( x-4) = 387`

   `→461+x-4=387`

   `→457+x=387`

   `→x=387-457`

   `→x=-70`

   Vậy `x=-70`

   `b)11- ( – 53 + x) = 97`

   `→11+53-x=97`

   `→64-x=97`

   `→x=64-97`

   `→x=-33`

   Vậy `x=-33`

   `c)-( x+84 ) + 213 = -16`

   `→-x-84+213=-16`

   `→-x+129=-16`

   `→-x=-16-129`

   `→-x=-145`

   `→x=145`

   Vậy `x=145`

   `d)3- ( 17-x) = 289 – ( 36 + 289)`

   `→3-17+x=289-325`

   `→-14+x=-36`

   `→x=-36+14`

   `→x=-22`

   Vậy `x=-22`

   `e) 25 – ( x+5 ) = 415 – ( 15 – 415)`

   `→25-x-5=415-(-400)`

   `→20-x=815`

   `→x=20-815`

   `→x=-795`

   Vậy `x=-795`

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2. a)

   `461+ (x – 4) = 387`

   ⇒ `461 +x – 4 = 387`

   ⇒ `x = 387+4- 461`

   ⇒ `x =-70`

    b)

   `11 – (-53+x) = 97`

   ⇒ `11+ 53 – x = 97`

   ⇒ `x =-33`

   c)

   `-(x+84)+213 = -16`

   ⇒ `-x-84+213 = -16`

   ⇒ `x = -145`

   d)

   `3 – (17-x) = 289 – (36+289)`

   ⇒ ` 3 – (17-x) = -36`

   ⇒ `17 – x =39`

   ⇒ `x = -22`

   e)

   `25 – (x+5) = 415 – (15 – 415)`

   ⇒ `x = 25 – (415 – 15 + 415) – 5`

   ⇒ `x = -795`

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