Đáp án:
tham khảo
Giải thích các bước giải:
`a)` `x-3/10=7/15÷3/5`
`=>x-3/10=7/15×5/3`
`=>x-3/10=7/9`
`=>x=7/9+3/10`
`=>x=97/90`
`b)` `8/23×46/23=1/3x`
`=>16/23=1/3x`
`=>x=16/23÷1/3`
`=>x=16/23×3`
`=>x=48/23`
`c)` `x÷(-1(3)/23)÷3(1)/2=-1(3)/4`
`=>x÷(-26)/23÷7/2=(-7)/4`
`=>x×(-23)/26×2/7=(-7)/4`
`=>x×(-23)/91=(-7)/4`
`=>x=(-7)/4÷(-23)/91`
`=>x=637/92`
`d)` `x-25%×x=0,5`
`=>x-1/4×x=1/2`
`=> (4x)/4 - x/4 = 2/4 `
`=>3x = 2`
`=>x=2÷3`
`=>x = 2/3 `