Tìm x ∈ Z a) 102+3.(x-71)=-12-39 b) 41-196 : (2x-1)=25-33 c)13-7.|31-x|=13 GIÚP MÌNH VỚI Ạ (lưu ý:*Toán lp6)

0 bình luận về “Tìm x ∈ Z a) 102+3.(x-71)=-12-39 b) 41-196 : (2x-1)=25-33 c)13-7.|31-x|=13 GIÚP MÌNH VỚI Ạ (lưu ý:*Toán lp6)”

1. $a$) `102+3.(x-71)=-12-39`

   `⇔ 102 + 3.(x-71) = -51`

   `⇔ 3.(x-71) = -153`

   `⇔ x-71 = -51`

   `⇔ x = 20`

     Vậy $x=20$

   $b$) `41-196 : (2x-1)=25-33`

   `⇔ 41 – 196:(2x-1) = -8`

   `⇔ 196:(2x-1) = 49`

   `⇔ 2x-1 = 4`

   `⇔ x = 5/2`

     Vậy `x=5/2`

   $c$) `13-7.|31-x|=13`

   `⇔ 7.|31-x| = 0`

   `⇔ |31-x| = 0`

   `⇔ x =31`

     Vậy $x=31$

    

   Bình luận

2. `a) 102 + 3 . (x – 71) = (-12) – 39`

   `102 + 3 . (x – 71) = -51`

   `3 . (x – 71) = (-51) – 102`

   `3 . (x – 71) = -153`

   `x – 71 = (-153) : 3`

   `x – 71 = -51`

   `x = (-51) + 71`

   `x = 20.`

   `b) 41 – 196 : (2x – 1) = 25 – 33`

   `41 – 196 : (2x – 1) = -8`

   `196 : (2x – 1) = 41 – (-8)`

   `196 : (2x – 1) = 49`

   `2x – 1 = 196 : 49`

   `2x – 1 = 4`

   `2x = 4 + 1`

   `2x = 5`

   `x = 5/2.`

   `c) 13 – 7 . |31 – x| = 13`

   `7 . |31 – x| = 13 – 13`

   `7 . |31 – x| = 0`

   `|31 – x| = 0`

   `31 – x = 0`

   `x = 0 + 31`

   `x = 31.`

   Bình luận