Tìm x `3/2 .(x-4/9)=4/7.(7-1/4)-1/3` `1/4 .( 8/3- x)+1/5= -3/4 . ( 1/2 - 1)`

Đáp án:

a, `x=176/63`

b, `x=59/30`

Giải thích các bước giải:

a,

`3/2 . (x-4/9)=4/7 . (7-1/4)-1/3`

`=>3/2 . (x-4/9)=4/7 . 27/4 -1/3`

`=>3/2 . (x-4/9)=27/7 - 1/3`

`=>3/2 . (x-4/9)=74/21`

`=>x-4/9=74/21:3/2`

`=>x-4/9=148/63`

`=>x=148/63+4/9`

`=>x=176/63`

Vậy `x=176/63`

b,

`1/4 . (8/3-x)+1/5=-3/4 . (1/2-1)`

`=>1/4 . (8/3-x)+1/5=-3/4 . (-1/2)`

`=>1/4 . (8/3-x)+1/5=3/8`

`=>1/4 . (8/3-x)=3/8-1/5`

`=>1/4 . (8/3-x)=7/40`

`=>8/3-x=7/40:1/4`

`=>8/3-x=7/10`

`=>x=8/3-7/10`

`=>x=59/30`

Vậy `x=59/30`