=>x+20=-15

hay x=-35

\(\Leftrightarrow x+20=-15\)

hay x=-35

25+(x-5)=-415-(-400)

25+(x-5)=-415+400

25+(x-5)=-15

x-5=-15-25

x-5=-40

x=-40+5

x=-35

Mai thi tận 2 môn chính, dễ ợt m :)

\(25+\left(x-5\right)=-15\\ x-5=\left(-15\right)-25=\left(-40\right)\\ x=\left(-40\right)+5=-35\)

a,  | x + 3 | - 12 = | -5 |

    x + 3  -  12  =  5

   x + 3  = 5 + 12

  x + 3  =  17

  x   =  17 - 3  = 14 

b,  25 - ( x- 5 ) = 415 x ( 15 - 415 )

25 - ( x - 5 )    =  415 x ( - 400 )

25 - ( x - 5 )    =   - 166000

      x - 5         =    25 - ( - 166000)

 x -  5            =     166025

x                   =    166025  +  5

x                   =      166030

CHÚC BẠN HỌC TỐT 

25-(x+5)= -415 - (15 - 415)

<=> 25 - x - 5 = -415 - 15 + 415

<=> -x = -415 -15 + 415 - 25 

<=> -x = -40

<=> x = 40 

k ghi lại đề nha :>

\(25-x-5=415-\left(-400\right)\))

20 - x = -415 + 400 

20 - x = -15 

-x = -15 - 20 

-x = -35 

x = 35 

25-(x+5)=15

x+5=25-15

x+5=10

x=10-5

x=5

\(a)484+x=\left(-632\right)+\left(-548\right)\)

\(484+x=-1180\)

\(x=(-1180)-484\)

\(x=-1664\)

\(b)\left(-x\right)+\left(-62\right)+\left(-46\right)=-14\)

\(\left(-x\right)+\left(-62\right)=-14-\left(-46\right)\)

\(\left(-x\right)+\left(-62\right)=-14+46\)

\(\left(-x\right)+\left(-62\right)=32\)

\(\left(-x\right)=32-\left(-62\right)\)

\(\left(-x\right)=32+62\)

\(\left(-x\right)=94\)

\(\Rightarrow x=94\)

\(c)25+\left(x-5\right)=-415-\left(15-415\right)\)

\(25+\left(x-5\right)=-415-\left(-400\right)\)

\(25+\left(x-5\right)=-415+400\)

\(25+\left(x-5\right)=-15\)

\(x-5=-15-25\)

\(x-5=-40\)

\(x=-40+5\)

\(x=-35\)

thank you @lê thị thanh huyền