tìm x biết a) x-14=20 b)x-320:32=25.16 c)(x-120).9=450 d) 128+(202-x)=330 e) 315- (135-x)=215 f) 25-(2.x+10)=5

Đáp án+Giải thích các bước giải:

`a)`

`x-14=20`

`=>x=20+14`

`=>x=34`

Vậy `x=34`

`b)`

`x-320:32=25.16`

`=>x-10=400`

`=>x=400+10`

`=>x=410`

Vậy `x=410`

`c)`

`(x-120).9=450`

`=>x-120=450:9`

`=>x-120=50`

`=>x=50+120`

`=>x=170`

Vậy `x=170`

`d)`

`128+(202-x)=330`

`=>202-x=330-128`

`=>202-x=202`

`=>x=202-202`

`=>x=0`

Vậy `x=0`

`e)`

`315-(135-x)=215`

`=>135-x=315-215`

`=>135-x=100`

`=>x=135-100`

`=>x=35`

Vậy `x=35`

`f)`

`25-(2.x+10)=5`

`=>2.x+10=25-5`

`=>2.x+10=20`

`=>2.x=20-10`

`=>2.x=10`

`=>x=10:2`

`=>x=5`

Vậy `x=5`