a) 1+7+8+15+23+…..+160 b)1+4+5+9+14+….+60+97 c78.31+78.24+78.17+22.72 m.n giải hộ mình vs ạ!!! 01/08/2021 Bởi Allison a) 1+7+8+15+23+…..+160 b)1+4+5+9+14+….+60+97 c78.31+78.24+78.17+22.72 m.n giải hộ mình vs ạ!!!
Đáp án: a. Ta có: `1+7=8` `7+8= 15` `A= 1+7+8+15+23+38+61+99+160` `= 8+8+38+38+160+160` `= (8+38+160).2` `= 206.2` `=412` b.Ta có `1+4=5` `5+9=14` ` B = 1+4+5+9+14+23+37+60+97` `= 5+5+23+23+97+97` `= (5+23+97).2` `=125.2` `=250` `c. 78.31+78.24+78.17+22.72` `= 78.(31+24+17) +22.72` `= 78.72+22.72 ` `= 72.(78+22) ` `= 72.100 ` `= 7200` $@lam$ Bình luận
đây nhé
Đáp án:
a. Ta có:
`1+7=8`
`7+8= 15`
`A= 1+7+8+15+23+38+61+99+160`
`= 8+8+38+38+160+160`
`= (8+38+160).2`
`= 206.2`
`=412`
b.Ta có
`1+4=5`
`5+9=14`
` B = 1+4+5+9+14+23+37+60+97`
`= 5+5+23+23+97+97`
`= (5+23+97).2`
`=125.2`
`=250`
`c. 78.31+78.24+78.17+22.72`
`= 78.(31+24+17) +22.72`
`= 78.72+22.72 `
`= 72.(78+22) `
`= 72.100 `
`= 7200`
$@lam$