Đáp án:
`b)x=-5`
`c)x=1/4`
Giải thích các bước giải:
`b)x-25%x-1/2x=-1(1)/4`
`x-1/4x-1/2x=-5/4`
`(1-1/4-1/2)x=-5/4`
`(4/4-1/4-2/4)x=-5/4`
`1/4x=-5/4`
`x=(-5/4):1/4`
`x=(-5/4).4`
`x=-5`
Vậy `x=-5`
`c)(11x-3/4)^3+21(9)/17=29(9)/17`
`(11x-3/4)^3=29(9)/17-21(9)/17`
`(11x-3/4)^3=8`
`(11x-3/4)^3=2^3`
`11x-3/4=2`
`11x=2+3/4`
`11x=8/4+3/4`
`11x=11/4`
`x=11/4:11`
`x=11/4 . 1/11`
`x=1/4`
Vậy `x=1/4`