Toán 1/90-1/72-1/56-1/42-1/30-1/20-1/12-1/6-1/2 18/11/2021 By Cora 1/90-1/72-1/56-1/42-1/30-1/20-1/12-1/6-1/2
Đáp án: `↓↓` Giải thích các bước giải: `1/90-1/72-1/56-1/42-1/30-1/20-1/12-1/6-1/2` `=1/90-(1/2+1/6+1/12+1/20+1/30+1/42+1/56+1/72)` `=1/90-(1/(1.2)+1/(2.3)+1/(3.4)+1/(4.5)+1/(5.6)+1/(6.7)+1/(7.8)+1/(8.9))` `=1/90-(1/1-1/2+1/2-1/3+1/3-1/4+1/4-1/5+1/5-1/6+1/6-1/7+1/7-1/8+1/8-1/9)` `=1/(9.10)-(1/1-1/9)` `=1/9-1/10-1/1+1/9` `=2/9-11/10` `=-79/90` Trả lời
Đáp án: `-(79)/90` Giải thích các bước giải: `1/90-1/72-1/56-1/42-1/30-1/20-1/12-1/6-1/2` `=1/90 – (1/72+1/56+1/42+1/30+1/20+1/12+1/6+1/2)` `=1/90-(1/2+1/6+1/12+1/20+1/30+1/42+1/56+1/72)` `=1/90-(1/(1.2)+1/(2.3)+1/(3.4)+1/(4.5)+1/(5.6)+1/(6.7)+1/(7.8)+1/(8.9))` `=1/90-(1-1/2+1/2-1/3+1/3-1/4+…+1/8-1/9)` `=1/90-(1-1/9)` `=1/90-8/9` `=-(79)/(90)` Trả lời
Đáp án:
`↓↓`
Giải thích các bước giải:
`1/90-1/72-1/56-1/42-1/30-1/20-1/12-1/6-1/2`
`=1/90-(1/2+1/6+1/12+1/20+1/30+1/42+1/56+1/72)`
`=1/90-(1/(1.2)+1/(2.3)+1/(3.4)+1/(4.5)+1/(5.6)+1/(6.7)+1/(7.8)+1/(8.9))`
`=1/90-(1/1-1/2+1/2-1/3+1/3-1/4+1/4-1/5+1/5-1/6+1/6-1/7+1/7-1/8+1/8-1/9)`
`=1/(9.10)-(1/1-1/9)`
`=1/9-1/10-1/1+1/9`
`=2/9-11/10`
`=-79/90`
Đáp án:
`-(79)/90`
Giải thích các bước giải:
`1/90-1/72-1/56-1/42-1/30-1/20-1/12-1/6-1/2`
`=1/90 – (1/72+1/56+1/42+1/30+1/20+1/12+1/6+1/2)`
`=1/90-(1/2+1/6+1/12+1/20+1/30+1/42+1/56+1/72)`
`=1/90-(1/(1.2)+1/(2.3)+1/(3.4)+1/(4.5)+1/(5.6)+1/(6.7)+1/(7.8)+1/(8.9))`
`=1/90-(1-1/2+1/2-1/3+1/3-1/4+…+1/8-1/9)`
`=1/90-(1-1/9)`
`=1/90-8/9`
`=-(79)/(90)`