125+75×(-34)-34×25 2x-4=x+9+(-18) 3x-12=-14+x 2x-7=x+9+(-19) 4x-12=-24+x 2×(x-3)=-x+(-18) 2×(x-3)=-x+(-15) 12+x=8-x (-52)×38-38×34+86×62 156-56×46+(-5

0 bình luận về “125+75×(-34)-34×25 2x-4=x+9+(-18) 3x-12=-14+x 2x-7=x+9+(-19) 4x-12=-24+x 2×(x-3)=-x+(-18) 2×(x-3)=-x+(-15) 12+x=8-x (-52)×38-38×34+86×62 156-56×46+(-5”

1. Đáp án-Giải thích các bước giải:

   `125 + 75 × ( – 34 ) – 34 × 25`

   `=125+34.(-75-25)`

   `=125+34.(-100)`

   `=125-3400`

   `=-3275`

   ________________________________

   ` 2x-4 = x + 9 + ( -18 )`

   `<=> 2x – 4 = x – 9`

   `<=> 2x – x = -9 + 4`

   `<=> x = -5 .`

   Vậy` x = -5`

   __________________________________

   `3x – 12 = -14 + x`

   `<=> 3x – x = -14 + 12`

   `<=> 2x = -2`

   `<=> x = -1 .`

   Vậy` x = -1`

   ________________________________

   ` 2x – 7 = x + 9 + ( -19 )`

   `<=> 2x – 7 = x – 10`

   `<=> 2x -x = -10 + 7`

   `<=> x = -3 .`

   Vậy `x = -3`

   ____________________________________

   `4x – 12 = -24 + x`

   `<=> 4x – x = -24 + 12`

   `<=> 3x = -12`

   `<=> x = -4 .`

   Vậy `x = -4`

   __________________________________

   `2×(x-3)=-x+(-18)`

   `<=> 2x – 6 = -x – 18`

   `<=> 2x + x = -18 + 6`

   `<=> 3x = -12`

   `<=> x = -4 `

   Vậy `x = -4`

   _________________________________

   `2 × ( x – 3 ) = -x + ( -15 )`

   `<=> 2x – 6 = -x – 15`

   `<=> 2x + x = -15 + 6`

   `<=> 3x = -9`

   `<=> x = -3 .`

   Vậy` x = -3`

   ___________________________________

   ` 12 + x = 8 – x`

   `<=> x + x = 8 – 12`

   `<=> 2x = -4`

   `<=> x = -2 `

   Vậy` x = -2`

   ____________________________________

   ` (-52)×38-38×34+86×62`

   `=38.(-52-34)+86.62`

   `=38.(-86)+86.62`

   `=86(-38+62)`

   `=86.24=2064`

   __________________________________

   `156-56×46+(-54)×56`

   `=156+56.(-46-54)`

   `=156+56.(-100)`

   `=156-5600`

   `=-5444`

   Trả lời

2. 1) 125 + 75 x ( – 34 ) – 34 x 25

   = 125 – 2550 – 850

   = – 3275

   2) 2x-4 = x + 9 + ( -18 )

   <=> 2x – 4 = x – 9

   <=> 2x – x = -9 + 4

   <=> x = -5 . Vậy x = -5

   3) 3x – 12 = -14 + x

   <=> 3x – x = -14 + 12

   <=> 2x = -2

   <=> x = -1 . Vậy x = -1

   4) 2x – 7 = x + 9 + ( -19 )

   <=> 2x – 7 = x – 10

   <=> 2x -x = -10 + 7

   <=> x = -3 . Vậy x = -3

   5) 4x – 12 = -24 + x

   <=> 4x – x = -24 + 12

   <=> 3x = -12

   <=> x = -4 . Vậy x = -4

   6) 2 x ( x – 3 ) = -x + ( -18 )

   <=> 2x – 6 = -x – 18

   <=> 2x + x = -18 + 6

   <=> 3x = -12

   <=> x = -4 . Vậy x = -4

   7) 2 x ( x – 3 ) = -x + ( -15 )

   <=> 2x – 6 = -x – 15

   <=> 2x + x = -15 + 6

   <=> 3x = -9

   <=> x = -3 . Vậy x = -3

   8) 12 + x = 8 – x

   <=> x + x = 8 – 12

   <=> 2x = -4

   <=> x = -2 .Vậy x = -2

   9) (-52)×38-38×34+86×62

   = -1976 – 1292 + 5332

   = 2064

   10) 156-56×46+(-54)×56

   = 156 – 2576 – 3024

   = -5444

    

   Trả lời