Đáp án:
Giải thích các bước giải:
`(x-29)/1970+(x-27)/1972+(x-25)/1974+(x-23)/1976+(x-21)/1978+(x-19)/1980=(x-1970)/29+(x-1972)/27+(x-1974)/25+(x-1976)/23+(x-1928)/21+(x-1980)/19`
`=> ((x-29)/1970-1)+((x-27)/1972-1)+((x-25)/1974-1)+((x-23)/1976-1)+((x-21)/1978-1)+((x-19)/1980-1)=((x-1970)/29-1)+((x-1972)/27-1)+((x-1974)/25-1)+((x-1976)/23-1)+((x-1928)/21-1)+((x-1980)/19-1)`
`<=> (x-29-1970)/1970+(x-27-1972)/1972+(x-25-1974)/1974+(x-23-1976)/1976+(x-21-1978)/1978+(x-19-1980)/1980=(x-1979-29)/29+(x-192-27)/27+(x-1974-25)/25+(x-1976-23)/23+(x-1928-21)/21+(x-1980-19)/19`
`<=> (x-1999)/1970+(x-1999)/1972+(x-1999)/1974+(x-1999)/1976+(x-1999)/1978+(x-1999)/1980=(x-1999)/29+(x-1999)/27+(x-1999)/25+(x-1999)/23+(x-1999)/21+(x-1999)/19`
`<=> (x-1999)/1970+(x-1999)/1972+(x-1999)/1974+(x-1999)/1976+(x-1999)/1978+(x-1999)/1980-(x-1999)/29-(x-1999)/27-(x-1999)/25-(x-1999)/23-(x-1999)/21-(x-1999)/19=0`
`<=> (x-1999).(1/1970+1/1972+1/1974+1/1976+1/1978+1/1980-1/29-1/27-1/25-1/23-1/21-1/19)=0`
Mà `1/1970+1/1972+1/1974+1/1976+1/1978+1/1980-1/29-1/27-1/25-1/23-1/21-1/19 ne 0`
`=> x-1999=0`
`<=> x=1999`
Vậy tập nghiệm của phương trình là `S={1999}`
