Tính nhanh: $\frac{108}{120}+\frac{104}{130}+\frac{98}{140}+\frac{90}{150}+\frac{80}{160}+\frac{68}{170}+\frac{54}{180}+\frac{38}{190}+\frac{1}{10}$
Tính nhanh: $\frac{108}{120}+\frac{104}{130}+\frac{98}{140}+\frac{90}{150}+\frac{80}{160}+\frac{68}{170}+\frac{54}{180}+\frac{38}{190}+\frac{1}{10}$
Giải thích các bước giải:
`108/120+104/130+98/140+90/150+80/160+68/170+54/180+38/190+1/10`
`=9/10+4/5+7/10+3/5+1/2+2/5+3/10+1/5+1/10`
`=(9/10+1/10)+(4/5+1/5)+(7/10+3/10)+(3/5+2/5)+1/2`
`=4+1/2`
`=9/2`
Đáp án:
`108/120+104/130+98/140+90/150+80/160+68/170+54/180+38/190+1/10=9/2`
Giải thích các bước giải:
Ta có: `108/120+104/130+98/140+90/150+80/160+68/170+54/180+38/190+1/10`
`=(108/120+1/10)+(104/130+38/190)+(98/140+54/180)+(90/150+68/170)+80/160`
`=(9/10+1/10)+(4/5+1/5)+(7/10+3/10)+(3/5+2/5)+1/2`
`=1+1+1+1`
`=4+1/2`
`=9/2`